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Msackyi M, Chen Y, Tsering W, Wang N, Zhang H. Dopamine Release Neuroenergetics in Mouse Striatal Slices. Int J Mol Sci 2024; 25:4580. [PMID: 38731799 PMCID: PMC11083938 DOI: 10.3390/ijms25094580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 05/13/2024] Open
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder. Dopamine (DA) neurons in the substantia nigra pars compacta, which have axonal projections to the dorsal striatum (dSTR), degenerate in PD. In contrast, DA neurons in the ventral tegmental area, with axonal projections to the ventral striatum, including the nucleus accumbens (NAcc) shell, are largely spared. This study aims to uncover the relative contributions of glycolysis and oxidative phosphorylation (OxPhos) to DA release in the striatum. We measured evoked DA release in mouse striatal brain slices using fast-scan cyclic voltammetry applied every two minutes. Blocking OxPhos resulted in a greater reduction in evoked DA release in the dSTR when compared to the NAcc shell, while blocking glycolysis caused a more significant decrease in evoked DA release in the NAcc shell than in the dSTR. Furthermore, when glycolysis was bypassed in favor of direct OxPhos, evoked DA release in the NAcc shell decreased by approximately 50% over 40 min, whereas evoked DA release in the dSTR was largely unaffected. These results demonstrate that the dSTR relies primarily on OxPhos for energy production to maintain evoked DA release, whereas the NAcc shell depends more on glycolysis. Consistently, two-photon imaging revealed higher oxidation levels of DA terminals in the dSTR than in the NAcc shell. Together, these findings partly explain the selective vulnerability of DA terminals in the dSTR to degeneration in PD.
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Affiliation(s)
- Msema Msackyi
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA; (M.M.); (Y.C.); (W.T.); (N.W.)
| | - Yuanxin Chen
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA; (M.M.); (Y.C.); (W.T.); (N.W.)
- Department of Physiology & Pharmacology, Center for Neurological Disease Research, The University of Georgia, 501 D.W. Brooks Drive, Athens, GA 30602, USA
| | - Wangchen Tsering
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA; (M.M.); (Y.C.); (W.T.); (N.W.)
| | - Ninghan Wang
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA; (M.M.); (Y.C.); (W.T.); (N.W.)
| | - Hui Zhang
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA; (M.M.); (Y.C.); (W.T.); (N.W.)
- Department of Physiology & Pharmacology, Center for Neurological Disease Research, The University of Georgia, 501 D.W. Brooks Drive, Athens, GA 30602, USA
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2
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Del Franco AP, Newman EA. Astrocyte β-Adrenergic Receptor Activity Regulates NMDA Receptor Signaling of Medial Prefrontal Cortex Pyramidal Neurons. J Neurosci 2024; 44:e0990232023. [PMID: 37989594 PMCID: PMC10860478 DOI: 10.1523/jneurosci.0990-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 10/23/2023] [Accepted: 11/13/2023] [Indexed: 11/23/2023] Open
Abstract
Glutamate spillover from the synapse is tightly regulated by astrocytes, limiting the activation of extrasynaptically located NMDA receptors (NMDAR). The processes of astrocytes are dynamic and can modulate synaptic physiology. Though norepinephrine (NE) and β-adrenergic receptor (β-AR) activity can modify astrocyte volume, this has yet to be confirmed outside of sensory cortical areas, nor has the effect of noradrenergic signaling on glutamate spillover and neuronal NMDAR activity been explored. We monitored changes to astrocyte process volume in response to noradrenergic agonists in the medial prefrontal cortex of male and female mice. Both NE and the β-AR agonist isoproterenol (ISO) increased process volume by ∼20%, significantly higher than changes seen when astrocytes had G-protein signaling blocked by GDPβS. We measured the effect of β-AR signaling on evoked NMDAR currents. While ISO did not affect single stimulus excitatory currents of Layer 5 pyramidal neurons, ISO reduced NMDAR currents evoked by 10 stimuli at 50 Hz, which elicits glutamate spillover, by 18%. After isolating extrasynaptic NMDARs by blocking synaptic NMDARs with the activity-dependent NMDAR blocker MK-801, ISO similarly reduced extrasynaptic NMDAR currents in response to 10 stimuli by 18%. Finally, blocking β-AR signaling in the astrocyte network by loading them with GDPβS reversed the ISO effect on 10 stimuli-evoked NMDAR currents. These results demonstrate that astrocyte β-AR activity reduces extrasynaptic NMDAR recruitment, suggesting that glutamate spillover is reduced.
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Affiliation(s)
- Armani P Del Franco
- Department of Neuroscience, University of Minnesota, Minneapolis 55455, Minnesota
| | - Eric A Newman
- Department of Neuroscience, University of Minnesota, Minneapolis 55455, Minnesota
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3
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Kimble L, Twiddy JS, Berger JM, Forderhase AG, McCarty GS, Meitzen J, Sombers LA. Simultaneous, Real-Time Detection of Glutamate and Dopamine in Rat Striatum Using Fast-Scan Cyclic Voltammetry. ACS Sens 2023; 8:4091-4100. [PMID: 37962541 PMCID: PMC10683757 DOI: 10.1021/acssensors.3c01267] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 10/24/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023]
Abstract
Glutamate and dopamine (DA) represent two key contributors to striatal functioning, a region of the brain that is essential to motor coordination and motivated behavior. While electroanalytical techniques can be utilized for rapid, spatially resolved detection of DA in the interferent-rich brain environment, glutamate, a nonelectroactive analyte, cannot be directly detected using electroanalytical techniques. However, it can be probed using enzyme-based sensors, which generate an electroactive reporter in the presence of glutamate. The vast majority of glutamate biosensors have relied on amperometric sensing, which is an inherently nonselective detection technique. This approach necessitates the use of complex and performance-limiting modifications to ensure the desired single-analyte specificity. Here, we present a novel glutamate microbiosensor fabricated on a carbon-fiber microelectrode substrate and coupled with fast-scan cyclic voltammetry (FSCV) to enable the simultaneous quantification of glutamate and DA at single recording sites in the brain, which is impossible when using typical amperometric approaches. The glutamate microbiosensors were characterized for sensitivity, stability, and selectivity by using a voltammetric waveform optimized for the simultaneous detection of both species. The applicability of these sensors for the investigation of neural circuits was validated in the rat ventral striatum. Electrically evoked glutamate and DA release were recorded at single-micrometer-scale locations before and after pharmacological manipulation of glutamatergic signaling. Our novel glutamate microbiosensor advances the state of the art by providing a powerful tool for probing coordination between these two species in a way that has previously not been possible.
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Affiliation(s)
- Laney
C. Kimble
- Department
of Chemistry, Department of Biological Sciences, and Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Jack S. Twiddy
- Department
of Chemistry, Department of Biological Sciences, and Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27695, United States
- Joint
Department of Biomedical Engineering, North
Carolina State University and University of North Carolina at Chapel
Hill, Raleigh, North Carolina 27695, United States
| | - Jenna M. Berger
- Department
of Chemistry, Department of Biological Sciences, and Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Alexandra G. Forderhase
- Department
of Chemistry, Department of Biological Sciences, and Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Gregory S. McCarty
- Department
of Chemistry, Department of Biological Sciences, and Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - John Meitzen
- Department
of Chemistry, Department of Biological Sciences, and Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Leslie A. Sombers
- Department
of Chemistry, Department of Biological Sciences, and Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27695, United States
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4
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Frare C, Pitt SK, Hewett SJ. Sex- and age-dependent contribution of System x c- to cognitive, sensory, and social behaviors revealed by comprehensive behavioral analyses of System x c- null mice. Front Behav Neurosci 2023; 17:1238349. [PMID: 37649973 PMCID: PMC10462982 DOI: 10.3389/fnbeh.2023.1238349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 07/31/2023] [Indexed: 09/01/2023] Open
Abstract
Background System xc- (Sxc-) is an important heteromeric amino acid cystine/glutamate exchanger that plays a pivotal role in the CNS by importing cystine into cells while exporting glutamate. Although certain behaviors have been identified as altered in Sxc- null mutant mice, our understanding of the comprehensive impact of Sxc- on behavior remains incomplete. Methods To address this gap, we compared motor, sensory and social behaviors of male and female mice in mice null for Sxc- (SLC7A11sut/sut) with wildtype littermates (SLC7A11+/+) in a comprehensive and systematic manner to determine effects of genotype, sex, age, and their potential interactions. Results Motor performance was not affected by loss of Sxc- in both males and females, although it was impacted negatively by age. Motor learning was specifically disrupted in female mice lacking Sxc- at both 2 and 6 months of age. Further, female SLC7A11sut/sut mice at both ages exhibited impaired sociability, but normal spatial and recognition memory, as well as sensorimotor gating. Finally, pronounced open-space anxiety was displayed by female SLC7A11sut/sut when they were young. In contrast, young SLC7A11sut/sut male mice demonstrated normal sociability, delayed spatial learning, increased open-space anxiety and heightened sensitivity to noise. As they aged, anxiety and noise sensitivity abated but hyperactivity emerged. Discussion We find that the behavioral phenotypes of female SLC7A11sut/sut are similar to those observed in mouse models of autism spectrum disorder, while behaviors of male SLC7A11sut/sut resemble those seen in mouse models of attention deficit hyperactivity disorder. These results underscore the need for further investigation of SLC7A11 in neurodevelopment. By expanding our understanding of the potential involvement of Sxc-, we may gain additional insights into the mechanisms underlying complex neurodevelopmental conditions.
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Affiliation(s)
| | | | - Sandra J. Hewett
- Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, NY, United States
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Rodríguez-Manzo G, Canseco-Alba A. The endogenous cannabinoid system modulates male sexual behavior expression. Front Behav Neurosci 2023; 17:1198077. [PMID: 37324524 PMCID: PMC10264596 DOI: 10.3389/fnbeh.2023.1198077] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/03/2023] [Indexed: 06/17/2023] Open
Abstract
The endocannabinoid system (ECS) plays a key neuromodulatory role in the brain. Main features of endocannabinoids (eCBs) are that they are produced on demand, in response to enhanced neuronal activity, act as retrograde messengers, and participate in the induction of brain plasticity processes. Sexual activity is a motivated behavior and therefore, the mesolimbic dopaminergic system (MSL) plays a central role in the control of its appetitive component (drive to engage in copulation). In turn, copulation activates mesolimbic dopamine neurons and repeated copulation produces the continuous activation of the MSL system. Sustained sexual activity leads to the achievement of sexual satiety, which main outcome is the transient transformation of sexually active male rats into sexually inhibited animals. Thus, 24 h after copulation to satiety, the sexually satiated males exhibit a decreased sexual motivation and do not respond to the presence of a sexually receptive female with sexual activity. Interestingly, blockade of cannabinoid receptor 1 (CB1R) during the copulation to satiety process, interferes with both the appearance of the long-lasting sexual inhibition and the decrease in sexual motivation in the sexually satiated males. This effect is reproduced when blocking CB1R at the ventral tegmental area evidencing the involvement of MSL eCBs in the induction of this sexual inhibitory state. Here we review the available evidence regarding the effects of cannabinoids, including exogenously administered eCBs, on male rodent sexual behavior of both sexually competent animals and rat sub populations spontaneously showing copulatory deficits, considered useful to model some human male sexual dysfunctions. We also include the effects of cannabis preparations on human male sexual activity. Finally, we review the role played by the ECS in the control of male sexual behavior expression with the aid of the sexual satiety phenomenon. Sexual satiety appears as a suitable model for the study of the relationship between eCB signaling, MSL synaptic plasticity and the modulation of male sexual motivation under physiological conditions that might be useful for the understanding of MSL functioning, eCB-mediated plasticity and their relationship with motivational processes.
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Affiliation(s)
- Gabriela Rodríguez-Manzo
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados (Cinvestav-Sede Sur), Ciudad de México, Mexico
| | - Ana Canseco-Alba
- Laboratorio de Fisiología de la Formación Reticular, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Ciudad de México, Mexico
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6
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Dopamine Release in Nucleus Accumbens Is under Tonic Inhibition by Adenosine A 1 Receptors Regulated by Astrocytic ENT1 and Dysregulated by Ethanol. J Neurosci 2022; 42:1738-1751. [PMID: 35042768 PMCID: PMC8896549 DOI: 10.1523/jneurosci.1548-21.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 11/20/2021] [Accepted: 11/23/2021] [Indexed: 11/21/2022] Open
Abstract
Striatal adenosine A1 receptor (A1R) activation can inhibit dopamine release. A1Rs on other striatal neurons are activated by an adenosine tone that is limited by equilibrative nucleoside transporter 1 (ENT1) that is enriched on astrocytes and is ethanol sensitive. We explored whether dopamine release in nucleus accumbens core is under tonic inhibition by A1Rs, and is regulated by astrocytic ENT1 and ethanol. In ex vivo striatal slices from male and female mice, A1R agonists inhibited dopamine release evoked electrically or optogenetically and detected using fast-scan cyclic voltammetry, most strongly for lower stimulation frequencies and pulse numbers, thereby enhancing the activity-dependent contrast of dopamine release. Conversely, A1R antagonists reduced activity-dependent contrast but enhanced evoked dopamine release levels, even for single optogenetic pulses indicating an underlying tonic inhibition. The ENT1 inhibitor nitrobenzylthioinosine reduced dopamine release and promoted A1R-mediated inhibition, and, conversely, virally mediated astrocytic overexpression of ENT1 enhanced dopamine release and relieved A1R-mediated inhibition. By imaging the genetically encoded fluorescent adenosine sensor [GPCR-activation based (GRAB)-Ado], we identified a striatal extracellular adenosine tone that was elevated by the ENT1 inhibitor and sensitive to gliotoxin fluorocitrate. Finally, we identified that ethanol (50 mm) promoted A1R-mediated inhibition of dopamine release, through diminishing adenosine uptake via ENT1. Together, these data reveal that dopamine output dynamics are gated by a striatal adenosine tone, limiting amplitude but promoting contrast, regulated by ENT1, and promoted by ethanol. These data add to the diverse mechanisms through which ethanol modulates striatal dopamine, and to emerging datasets supporting astrocytic transporters as important regulators of striatal function.SIGNIFICANCE STATEMENT Dopamine axons in the mammalian striatum are emerging as strategic sites where neuromodulators can powerfully influence dopamine output in health and disease. We found that ambient levels of the neuromodulator adenosine tonically inhibit dopamine release in nucleus accumbens core via adenosine A1 receptors (A1Rs), to a variable level that promotes the contrast in dopamine signals released by different frequencies of activity. We reveal that the equilibrative nucleoside transporter 1 (ENT1) on astrocytes limits this tonic inhibition, and that ethanol promotes it by diminishing adenosine uptake via ENT1. These findings support the hypotheses that A1Rs on dopamine axons inhibit dopamine release and, furthermore, that astrocytes perform important roles in setting the level of striatal dopamine output, in health and disease.
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7
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Brundage JN, Mason CP, Wadsworth HA, Finuf CS, Nelson JJ, Ronström PJW, Jones SR, Siciliano CA, Steffensen SC, Yorgason JT. Regional and sex differences in spontaneous striatal dopamine transmission. J Neurochem 2022; 160:598-612. [PMID: 34265080 PMCID: PMC10044475 DOI: 10.1111/jnc.15473] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 06/10/2021] [Accepted: 07/13/2021] [Indexed: 11/29/2022]
Abstract
Striatal dopamine release is key for learning and motivation and is composed of subregions including the dorsal striatum (DS), nucleus accumbens core, and the nucleus accumbens shell. Spontaneously occurring dopamine release was compared across these subregions. Dopamine release/uptake dynamics differ across striatal subregions, with dopamine transient release amplitude and release frequency greatest in male mice, and the largest signals observed in the DS. Surprisingly, female mice exhibited little regional differences in dopamine release for DS and nucleus accumbens core regions, but lower release in the nucleus accumbens shell. Blocking voltage-gated K+ channel (Kv channels) with 4-aminopyridine enhanced dopamine detection without affecting reuptake. The 4-aminopyridine effects were greatest in ventral regions of female mice, suggesting regional differences in Kv channel expression. The dopamine transporter blocker cocaine also enhanced detection across subregions in both sexes, with greater overall increased release in females than males. Thus, sex differences in dopamine transmission are apparent and likely include differences in the Kv channel and dopamine transporter function. The lack of regional differences in dopamine release observed in females indicates differential regulation of spontaneous and evoked dopamine release.
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Affiliation(s)
| | - Colin P. Mason
- Neuroscience Center, Brigham Young University, Provo, UT, USA
| | | | - Chris S. Finuf
- Department of Psychology and Neuroscience Center, Brigham Young University, Provo, UT, USA
| | - Josh J. Nelson
- Neuroscience Center, Brigham Young University, Provo, UT, USA
| | | | - Sara R. Jones
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, NC, USA
| | - Cody A. Siciliano
- Department of Pharmacology, Vanderbilt Brain Institute, Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN, USA
| | - Scott C. Steffensen
- Department of Psychology and Neuroscience Center, Brigham Young University, Provo, UT, USA
| | - Jordan T. Yorgason
- Neuroscience Center, Brigham Young University, Provo, UT, USA
- Department of Cellular Biology and Physiology, Brigham Young University, Provo, UT, USA
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8
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Hobson BD, Choi SJ, Mosharov EV, Soni RK, Sulzer D, Sims PA. Subcellular proteomics of dopamine neurons in the mouse brain. eLife 2022; 11:e70921. [PMID: 35098924 PMCID: PMC8860448 DOI: 10.7554/elife.70921] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 01/30/2022] [Indexed: 11/13/2022] Open
Abstract
Dopaminergic neurons modulate neural circuits and behaviors via dopamine (DA) release from expansive, long range axonal projections. The elaborate cytoarchitecture of these neurons is embedded within complex brain tissue, making it difficult to access the neuronal proteome using conventional methods. Here, we demonstrate APEX2 proximity labeling within genetically targeted neurons in the mouse brain, enabling subcellular proteomics with cell-type specificity. By combining APEX2 biotinylation with mass spectrometry, we mapped the somatodendritic and axonal proteomes of midbrain dopaminergic neurons. Our dataset reveals the proteomic architecture underlying proteostasis, axonal metabolism, and neurotransmission in these neurons. We find that most proteins encoded by DA neuron-enriched genes are localized within striatal dopaminergic axons, including ion channels with previously undescribed axonal localization. These proteomic datasets provide a resource for neuronal cell biology, and this approach can be readily adapted for study of other neural cell types.
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Affiliation(s)
- Benjamin D Hobson
- Department of Systems Biology, Columbia University Irving Medical CenterNew YorkUnited States
- Medical Scientist Training Program, Columbia University Irving Medical CenterNew YorkUnited States
- Department of Psychiatry, Columbia University Irving Medical CenterNew YorkUnited States
| | - Se Joon Choi
- Division of Molecular Therapeutics, New York State Psychiatric InstituteNew YorkUnited States
| | - Eugene V Mosharov
- Division of Molecular Therapeutics, New York State Psychiatric InstituteNew YorkUnited States
| | - Rajesh K Soni
- Proteomics Shared Resource, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical CenterNew YorkUnited States
| | - David Sulzer
- Department of Psychiatry, Columbia University Irving Medical CenterNew YorkUnited States
- Division of Molecular Therapeutics, New York State Psychiatric InstituteNew YorkUnited States
- Department of Neurology, Columbia University Irving Medical CenterNew YorkUnited States
- Department of Pharmacology, Columbia University Irving Medical CenterNew YorkUnited States
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research NetworkChevy ChaseUnited States
| | - Peter A Sims
- Department of Systems Biology, Columbia University Irving Medical CenterNew YorkUnited States
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research NetworkChevy ChaseUnited States
- Department of Biochemistry & Molecular Biophysics, Columbia University Irving Medical CenterNew YorkUnited States
- Sulzberger Columbia Genome Center, Columbia University Irving Medical CenterNew YorkUnited States
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9
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Mercuri NB, Federici M, Rizzo FR, Maugeri L, D'Addario SL, Ventura R, Berretta N. Long-Term Depression of Striatal DA Release Induced by mGluRs via Sustained Hyperactivity of Local Cholinergic Interneurons. Front Cell Neurosci 2021; 15:798464. [PMID: 34924961 PMCID: PMC8674918 DOI: 10.3389/fncel.2021.798464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 11/15/2021] [Indexed: 12/21/2022] Open
Abstract
The cellular mechanisms regulating dopamine (DA) release in the striatum have attracted much interest in recent years. By in vitro amperometric recordings in mouse striatal slices, we show that a brief (5 min) exposure to the metabotropic glutamate receptor agonist DHPG (50 μM) induces a profound depression of synaptic DA release, lasting over 1 h from DHPG washout. This long-term depression is sensitive to glycine, which preferentially inhibits local cholinergic interneurons, as well as to drugs acting on nicotinic acetylcholine receptors and to the pharmacological depletion of released acetylcholine. The same DHPG treatment induces a parallel long-lasting enhancement in the tonic firing of presumed striatal cholinergic interneurons, measured with multi-electrode array recordings. When DHPG is bilaterally infused in vivo in the mouse striatum, treated mice display an anxiety-like behavior. Our results demonstrate that metabotropic glutamate receptors stimulation gives rise to a prolonged depression of the striatal dopaminergic transmission, through a sustained enhancement of released acetylcholine, due to the parallel long-lasting potentiation of striatal cholinergic interneurons firing. This plastic interplay between dopamine, acetylcholine, and glutamate in the dorsal striatum may be involved in anxiety-like behavior typical of several neuropsychiatric disorders.
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Affiliation(s)
- Nicola B Mercuri
- IRCCS Fondazione Santa Lucia, Laboratory of Experimental Neurology, Rome, Italy.,Department of Systems Medicine, University of Tor Vergata, Rome, Italy
| | - Mauro Federici
- IRCCS Fondazione Santa Lucia, Laboratory of Experimental Neurology, Rome, Italy
| | | | - Lorenzo Maugeri
- IRCCS Fondazione Santa Lucia, Laboratory of Experimental Neurology, Rome, Italy
| | - Sebastian L D'Addario
- IRCCS Fondazione Santa Lucia, Laboratory of Experimental Neurology, Rome, Italy.,Department of Psychology and Center Daniel Bovet, Sapienza University, Rome, Italy.,Behavioral Neuroscience PhD Programme, Sapienza University, Rome, Italy
| | - Rossella Ventura
- IRCCS Fondazione Santa Lucia, Laboratory of Experimental Neurology, Rome, Italy.,Department of Psychology and Center Daniel Bovet, Sapienza University, Rome, Italy
| | - Nicola Berretta
- IRCCS Fondazione Santa Lucia, Laboratory of Experimental Neurology, Rome, Italy
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10
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LRRK2 signaling in neurodegeneration: two decades of progress. Essays Biochem 2021; 65:859-872. [PMID: 34897411 DOI: 10.1042/ebc20210013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/13/2021] [Accepted: 11/23/2021] [Indexed: 12/17/2022]
Abstract
Leucine-rich repeat kinase 2 (LRRK2) is a complex GTPase/kinase orchestrating cytoskeletal dynamics and multiple steps of the endolysosomal pathway through interaction with a host of partners and phosphorylation of a subset of Rab GTPases. Mutations in LRRK2 cause late-onset Parkinson's disease (PD) and common variants in the locus containing LRRK2 have been associated with sporadic PD, progressive supranuclear palsy as well as a number of inflammatory diseases. This review encompasses the major discoveries in the field of LRRK2 pathobiology, from the initial gene cloning to the latest progress in LRRK2 inhibition as a promising therapeutic approach to fight neurodegeneration.
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11
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Taspinar N, Hacimuftuoglu A, Butuner S, Togar B, Arslan G, Taghizadehghalehjoughi A, Okkay U, Agar E, Stephens R, Turkez H, Abd El-Aty AM. Differential effects of inhibitors of PTZ-induced kindling on glutamate transporters and enzyme expression. Clin Exp Pharmacol Physiol 2021; 48:1662-1673. [PMID: 34409650 DOI: 10.1111/1440-1681.13575] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 07/31/2021] [Accepted: 08/14/2021] [Indexed: 12/01/2022]
Abstract
Epilepsy is a neurological disorder resulting from abnormal neuronal firing in the brain. Glutamate transporters and the glutamate-glutamine cycle play crucial roles in the development of seizures. In the present study, the correlation of epilepsy with glutamate transporters and enzymes was investigated. Herein, male Wistar rats were randomly allocated into four groups (six animals/group); 35 mg/kg pentylenetetrazole (PTZ) was used to induce a kindling model of epilepsy. Once the kindling model was established, animals were treated for 15 days with either valproic acid (VPA, 350 mg/kg) or ceftriaxone (CEF, 200 mg/kg) in addition to the control group receiving saline. After treatment, electrocorticography (ECoG) was performed to record the electrical activity of the cerebral cortex. The glutamate reuptake time (T80 ) was also determined in situ using an in vivo voltammetry. The expression levels of glutamate transporters and enzymes in the M1 and CA3 areas of the brain were determined using a real-time polymerase chain reaction (RT-PCR). ECoG measurements showed that the mean spike number of the PTZ + VPA and PTZ + CEF groups was significantly lower (p < 0.05) than that of the PTZ group. Compared with the PTZ group, VPA or CEF treatment decreased the glutamate reuptake time (T80 ). The expression levels of EAAC1, GLT-1, GLAST, glutamine synthetase (GS), and glutaminase were increased in the PTZ group. Treatment with VPA or CEF enhanced the expression levels of GLT-1, GLAST, EAAC1, and GS, whereas the glutaminase expression level was reduced. The current results suggest that VPA or CEF decreases seizure activity by increasing glutamate reuptake by upregulating GLT-1 and GLAST expression, implying a possible mechanism for treating epilepsy. Also, we have suggested a novel mechanism for the antiepileptic activity of VPA via decreasing glutaminase expression levels. To our knowledge, this is the first study to measure the glutamate reuptake time in situ during the seizure (i.e., real-time measurement).
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Affiliation(s)
- Numan Taspinar
- Department of Medical Pharmacology, Faculty of Medicine, Uşak University, Uşak, Turkey
| | - Ahmet Hacimuftuoglu
- Department of Medical Pharmacology, Faculty of Medicine, Atatürk University, Erzurum, Turkey
| | - Selcuk Butuner
- Department of Medical Pharmacology, Faculty of Medicine, Atatürk University, Erzurum, Turkey
| | - Basak Togar
- Department of Medical Services and Techniques, Vocational School of Health Services, Bayburt University, Bayburt, Turkey
| | - Gokhan Arslan
- Department of Physiology, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey
| | - Ali Taghizadehghalehjoughi
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Atatürk University, Erzurum, Turkey
| | - Ufuk Okkay
- Department of Medical Pharmacology, Faculty of Medicine, Atatürk University, Erzurum, Turkey
| | - Erdal Agar
- Department of Physiology, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey
| | - Robert Stephens
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Hasan Turkez
- Department of Medical Biology, Faculty of Medicine, Atatürk University, Erzurum, Turkey
| | - A M Abd El-Aty
- Department of Medical Pharmacology, Faculty of Medicine, Atatürk University, Erzurum, Turkey
- Department of Pharmacology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
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12
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Crittenden JR, Zhai S, Sauvage M, Kitsukawa T, Burguière E, Thomsen M, Zhang H, Costa C, Martella G, Ghiglieri V, Picconi B, Pescatore KA, Unterwald EM, Jackson WS, Housman DE, Caine SB, Sulzer D, Calabresi P, Smith AC, Surmeier DJ, Graybiel AM. CalDAG-GEFI mediates striatal cholinergic modulation of dendritic excitability, synaptic plasticity and psychomotor behaviors. Neurobiol Dis 2021; 158:105473. [PMID: 34371144 PMCID: PMC8486000 DOI: 10.1016/j.nbd.2021.105473] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 07/21/2021] [Accepted: 08/02/2021] [Indexed: 01/19/2023] Open
Abstract
CalDAG-GEFI (CDGI) is a protein highly enriched in the striatum, particularly in the principal spiny projection neurons (SPNs). CDGI is strongly down-regulated in two hyperkinetic conditions related to striatal dysfunction: Huntington’s disease and levodopa-induced dyskinesia in Parkinson’s disease. We demonstrate that genetic deletion of CDGI in mice disrupts dendritic, but not somatic, M1 muscarinic receptors (M1Rs) signaling in indirect pathway SPNs. Loss of CDGI reduced temporal integration of excitatory postsynaptic potentials at dendritic glutamatergic synapses and impaired the induction of activity-dependent long-term potentiation. CDGI deletion selectively increased psychostimulant-induced repetitive behaviors, disrupted sequence learning, and eliminated M1R blockade of cocaine self-administration. These findings place CDGI as a major, but previously unrecognized, mediator of cholinergic signaling in the striatum. The effects of CDGI deletion on the self-administration of drugs of abuse and its marked alterations in hyperkinetic extrapyramidal disorders highlight CDGI’s therapeutic potential.
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Affiliation(s)
- Jill R Crittenden
- McGovern Institute for Brain Research and Dept. of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, MIT, Cambridge, MA 02139, USA
| | - Shenyu Zhai
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Magdalena Sauvage
- McGovern Institute for Brain Research and Dept. of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA; Leibniz Institute for Neurobiology, Functional Architecture of Memory Dept., Magdeburg, Germany
| | - Takashi Kitsukawa
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Eric Burguière
- McGovern Institute for Brain Research and Dept. of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA; Brain and Spine Institute (ICM), CNRS UMR 7225, INSERM U 1127, UPMC-P6 UMR S, 1127, Hôpital de la Pitié-Salpêtrière, 47 boulevard de l'hôpital, Paris, France
| | - Morgane Thomsen
- Laboratory of Neuropsychiatry, Psychiatric Centre Copenhagen and University, DK-2100, Copenhagen, Denmark; Basic Neuroscience Division, McLean Hospital/Harvard Medical School, Belmont, MA 02478, USA
| | - Hui Zhang
- Departments of Psychiatry, Pharmacology, Neurology, Columbia University, New York State Psychiatric Institute, New York, NY 10032, USA; Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Cinzia Costa
- Neurological Clinic, Department of Medicine, Hospital Santa Maria della misericordia, University of Perugia, 06100 Perugia, Italy
| | - Giuseppina Martella
- Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy
| | | | | | - Karen A Pescatore
- Department of Pharmacology and Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Ellen M Unterwald
- Department of Pharmacology and Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Walker S Jackson
- Wallenberg Center for Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, 581 83 Linköping, Sweden
| | - David E Housman
- Koch Institute for Integrative Cancer Research, MIT, Cambridge, MA 02139, USA
| | - S Barak Caine
- Basic Neuroscience Division, McLean Hospital/Harvard Medical School, Belmont, MA 02478, USA
| | - David Sulzer
- Departments of Psychiatry, Pharmacology, Neurology, Columbia University, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Paolo Calabresi
- Neurological Clinic, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy; Department of Neuroscience, Faculty of Medicine, Università Cattolica del "Sacro Cuore", 00168 Rome, Italy
| | - Anne C Smith
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85724, USA
| | - D James Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Ann M Graybiel
- McGovern Institute for Brain Research and Dept. of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA.
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13
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Obesity and dietary fat influence dopamine neurotransmission: exploring the convergence of metabolic state, physiological stress, and inflammation on dopaminergic control of food intake. Nutr Res Rev 2021; 35:236-251. [PMID: 34184629 DOI: 10.1017/s0954422421000196] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The aim of this review is to explore how metabolic changes induced by diets high in saturated fat (HFD) affect nucleus accumbens (NAc) dopamine neurotransmission and food intake, and to explore how stress and inflammation influence this process. Recent evidence linked diet-induced obesity and HFD with reduced dopamine release and reuptake. Altered dopamine neurotransmission could disrupt satiety circuits between NAc dopamine terminals and projections to the hypothalamus. The NAc directs learning and motivated behaviours based on homeostatic needs and psychological states. Therefore, impaired dopaminergic responses to palatable food could contribute to weight gain by disrupting responses to food cues or stress, which impacts type and quantity of food consumed. Specifically, saturated fat promotes neuronal resistance to anorectic hormones and activation of immune cells that release proinflammatory cytokines. Insulin has been shown to regulate dopamine neurotransmission by enhancing satiety, but less is known about effects of diet-induced stress. Therefore, changes to dopamine signalling due to HFD warrant further examination to characterise crosstalk of cytokines with endocrine and neurotransmitter signals. A HFD promotes a proinflammatory environment that may disrupt neuronal endocrine function and dopamine signalling that could be exacerbated by the hypothalamic-pituitary-adrenal and κ-opioid receptor stress systems. Together, these adaptive changes may dysregulate eating by changing NAc dopamine during hedonic versus homeostatic food intake. This could drive palatable food cravings during energy restriction and hinder weight loss. Understanding links between HFD and dopamine neurotransmission will inform treatment strategies for diet-induced obesity and identify molecular candidates for targeted therapeutics.
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14
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Cover KK, Mathur BN. Axo-axonic synapses: Diversity in neural circuit function. J Comp Neurol 2021; 529:2391-2401. [PMID: 33314077 PMCID: PMC8053672 DOI: 10.1002/cne.25087] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/20/2022]
Abstract
The chemical synapse is the principal form of contact between neurons of the central nervous system. These synapses are typically configured as presynaptic axon terminations onto postsynaptic dendrites or somata, giving rise to axo-dendritic and axo-somatic synapses, respectively. Beyond these common synapse configurations are less-studied, non-canonical synapse types that are prevalent throughout the brain and significantly contribute to neural circuit function. Among these are the axo-axonic synapses, which consist of an axon terminating on another axon or axon terminal. Here, we review evidence for axo-axonic synapse contributions to neural signaling in the mammalian nervous system and survey functional neural circuit motifs enabled by these synapses. We also detail how recent advances in microscopy, transgenics, and biological sensors may be used to identify and functionally assay axo-axonic synapses.
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Affiliation(s)
- Kara K. Cover
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD USA 21201
| | - Brian N. Mathur
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD USA 21201
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15
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Zachry JE, Nolan SO, Brady LJ, Kelly SJ, Siciliano CA, Calipari ES. Sex differences in dopamine release regulation in the striatum. Neuropsychopharmacology 2021; 46:491-499. [PMID: 33318634 PMCID: PMC8027008 DOI: 10.1038/s41386-020-00915-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 11/03/2020] [Accepted: 11/09/2020] [Indexed: 01/05/2023]
Abstract
The mesolimbic dopamine system-which originates in the ventral tegmental area and projects to the striatum-has been shown to be involved in the expression of sex-specific behavior and is thought to be a critical mediator of many psychiatric diseases. While substantial work has focused on sex differences in the anatomy of dopamine neurons and relative dopamine levels between males and females, an important characteristic of dopamine release from axon terminals in the striatum is that it is rapidly modulated by local regulatory mechanisms independent of somatic activity. These processes can occur via homosynaptic mechanisms-such as presynaptic dopamine autoreceptors and dopamine transporters-as well as heterosynaptic mechanisms, such as retrograde signaling from postsynaptic cholinergic and GABAergic systems, among others. These regulators serve as potential targets for the expression of sex differences in dopamine regulation in both ovarian hormone-dependent and independent fashions. This review describes how sex differences in microcircuit regulatory mechanisms can alter dopamine dynamics between males and females. We then describe what is known about the hormonal mechanisms controlling/regulating these processes. Finally, we highlight the missing gaps in our knowledge of these systems in females. Together, a more comprehensive and mechanistic understanding of how sex differences in dopamine function manifest will be particularly important in developing evidence-based therapeutics that target this system and show efficacy in both sexes.
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Affiliation(s)
- Jennifer E. Zachry
- grid.152326.10000 0001 2264 7217Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
| | - Suzanne O. Nolan
- grid.152326.10000 0001 2264 7217Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
| | - Lillian J. Brady
- grid.152326.10000 0001 2264 7217Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
| | - Shannon J. Kelly
- grid.152326.10000 0001 2264 7217Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
| | - Cody A. Siciliano
- grid.152326.10000 0001 2264 7217Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA ,grid.152326.10000 0001 2264 7217Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232 USA ,grid.152326.10000 0001 2264 7217Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN 37232 USA
| | - Erin S. Calipari
- grid.152326.10000 0001 2264 7217Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA ,grid.152326.10000 0001 2264 7217Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232 USA ,grid.152326.10000 0001 2264 7217Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN 37232 USA ,grid.152326.10000 0001 2264 7217Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232 USA ,grid.152326.10000 0001 2264 7217Department of Psychiatry and Behavioral Sciences, Vanderbilt University, Nashville, TN 37232 USA
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16
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Kramer PF, Twedell EL, Shin JH, Zhang R, Khaliq ZM. Axonal mechanisms mediating γ-aminobutyric acid receptor type A (GABA-A) inhibition of striatal dopamine release. eLife 2020; 9:e55729. [PMID: 32870779 PMCID: PMC7462615 DOI: 10.7554/elife.55729] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 08/15/2020] [Indexed: 01/03/2023] Open
Abstract
Axons of dopaminergic neurons innervate the striatum where they contribute to movement and reinforcement learning. Past work has shown that striatal GABA tonically inhibits dopamine release, but whether GABA-A receptors directly modulate transmission or act indirectly through circuit elements is unresolved. Here, we use whole-cell and perforated-patch recordings to test for GABA-A receptors on the main dopaminergic neuron axons and branching processes within the striatum of adult mice. Application of GABA depolarized axons, but also decreased the amplitude of axonal spikes, limited propagation and reduced striatal dopamine release. The mechanism of inhibition involved sodium channel inactivation and shunting. Lastly, we show the positive allosteric modulator diazepam enhanced GABA-A currents on dopaminergic axons and directly inhibited release, but also likely acts by reducing excitation from cholinergic interneurons. Thus, we reveal the mechanisms of GABA-A receptor modulation of dopamine release and provide new insights into the actions of benzodiazepines within the striatum.
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Affiliation(s)
- Paul F Kramer
- Cellular Neurophysiology Unit, National Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaUnited States
| | - Emily L Twedell
- Cellular Neurophysiology Unit, National Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaUnited States
| | - Jung Hoon Shin
- Laboratory on Neurobiology of Compulsive Behaviors, National Institute of Alcohol Abuse and Alcoholism, National Institutes of HealthBethesdaUnited States
| | - Renshu Zhang
- Cellular Neurophysiology Unit, National Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaUnited States
| | - Zayd M Khaliq
- Cellular Neurophysiology Unit, National Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaUnited States
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17
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Iovino L, Tremblay ME, Civiero L. Glutamate-induced excitotoxicity in Parkinson's disease: The role of glial cells. J Pharmacol Sci 2020; 144:151-164. [PMID: 32807662 DOI: 10.1016/j.jphs.2020.07.011] [Citation(s) in RCA: 155] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/30/2020] [Accepted: 07/27/2020] [Indexed: 12/11/2022] Open
Abstract
Glutamate is the major excitatory neurotransmitter in the central nervous system. Glutamate transmission efficiency depends on the correct functionality and expression of a plethora of receptors and transporters, located both on neurons and glial cells. Of note, glutamate reuptake by dedicated transporters prevents its accumulation at the synapse as well as non-physiological spillover. Indeed, extracellular glutamate increase causes aberrant synaptic signaling leading to neuronal excitotoxicity and death. Moreover, extrasynaptic glutamate diffusion is strongly associated with glia reaction and neuroinflammation. Glutamate-induced excitotoxicity is mainly linked to an impaired ability of glial cells to reuptake and respond to glutamate, then this is considered a common hallmark in many neurodegenerative diseases, including Parkinson's disease (PD). In this review, we discuss the function of astrocytes and microglia in glutamate homeostasis, focusing on how glial dysfunction causes glutamate-induced excitotoxicity leading to neurodegeneration in PD.
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Affiliation(s)
- L Iovino
- Department of Biology, University of Padova, Italy
| | - M E Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, Canada
| | - L Civiero
- Department of Biology, University of Padova, Italy; IRCCS San Camillo Hospital, Venice, Italy.
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18
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Puts NA, Ryan M, Oeltzschner G, Horska A, Edden RAE, Mahone EM. Reduced striatal GABA in unmedicated children with ADHD at 7T. Psychiatry Res Neuroimaging 2020; 301:111082. [PMID: 32438277 DOI: 10.1016/j.pscychresns.2020.111082] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 12/12/2022]
Abstract
Attention-deficit hyperactive disorder (ADHD) is characterized by inattention and increased impulsive and hypermotoric behaviors.Despite the high prevalence and impact of ADHD, little is known about the underlying neurophysiology of ADHD. The main inhibitory and excitatory neurotransmitters γ-aminobutyric acid (GABA) and glutamate are receiving increased attention in ADHD and can be measured using Magnetic Resonance Spectroscopy (MRS). However, MRS studies in ADHD are limited. We measured GABA and glutamate in young unmedicated participants, utilizing high magnetic field strength. Fifty unmedicated children (26 with ADHD, 24 controls) aged 5-9 years completed MRS at 7T and behavioral testing. GABA and glutamate were measured in dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), premotor cortex (PMC), and striatum, and estimated using LCModel. Children with ADHD showed poorer inhibitory control and significantly reduced GABA/Cr in the striatum, but not in ACC, DLPFC, or PMC regions. There were no significant group differences for Glu/Cr levels, or correlations with behavioral manifestations of ADHD. The primary finding of this study is a reduction of striatal GABA levels in unmedicated children with ADHD at 7T. These findings provide guidance for future studies or interventions. Reduced striatal GABA may be a marker for specific GABA-related treatment for ADHD.
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Affiliation(s)
- Nicolaas A Puts
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 600 N Wolfe St., Baltimore, MD 21287, United States; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N Broadway, Baltimore, MD 21205, United States; Department of Forensic and Neurodevelopmental Sciences, Sackler Institute for Translational Neurodevelopment, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 16 De Crespigny Park, London, SE5 8AB, United Kingdom.
| | - Matthew Ryan
- Department of Neuropsychology, Kennedy Krieger Institute, 1750 E. Fairmount Ave., Baltimore, MD 21231 United States
| | - Georg Oeltzschner
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 600 N Wolfe St., Baltimore, MD 21287, United States; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N Broadway, Baltimore, MD 21205, United States
| | - Alena Horska
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 600 N Wolfe St., Baltimore, MD 21287, United States
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 600 N Wolfe St., Baltimore, MD 21287, United States; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N Broadway, Baltimore, MD 21205, United States
| | - E Mark Mahone
- Department of Neuropsychology, Kennedy Krieger Institute, 1750 E. Fairmount Ave., Baltimore, MD 21231 United States; Department of Psychiatry and Behavioral Sciences, The Johns Hopkins University School of Medicine, 600 N Wolfe St., Baltimore, MD 21287, United States
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19
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Nolan SO, Zachry JE, Johnson AR, Brady LJ, Siciliano CA, Calipari ES. Direct dopamine terminal regulation by local striatal microcircuitry. J Neurochem 2020; 155:475-493. [PMID: 32356315 DOI: 10.1111/jnc.15034] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 04/20/2020] [Accepted: 04/22/2020] [Indexed: 02/06/2023]
Abstract
Regulation of axonal dopamine release by local microcircuitry is at the hub of several biological processes that govern the timing and magnitude of signaling events in reward-related brain regions. An important characteristic of dopamine release from axon terminals in the striatum is that it is rapidly modulated by local regulatory mechanisms. These processes can occur via homosynaptic mechanisms-such as presynaptic dopamine autoreceptors and dopamine transporters - as well heterosynaptic mechanisms such as retrograde signaling from postsynaptic cholinergic and dynorphin systems, among others. Additionally, modulation of dopamine release via diffusible messengers, such as nitric oxide and hydrogen peroxide, allows for various metabolic factors to quickly and efficiently regulate dopamine release and subsequent signaling. Here we review how these mechanisms work in concert to influence the timing and magnitude of striatal dopamine signaling, independent of action potential activity at the level of dopaminergic cell bodies in the midbrain, thereby providing a parallel pathway by which dopamine can be modulated. Understanding the complexities of local regulation of dopamine signaling is required for building comprehensive frameworks of how activity throughout the dopamine system is integrated to drive signaling and control behavior.
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Affiliation(s)
- Suzanne O Nolan
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Jennifer E Zachry
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Amy R Johnson
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Lillian J Brady
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Cody A Siciliano
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA.,Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA.,Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN TN, USA
| | - Erin S Calipari
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA.,Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA.,Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN TN, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.,Department of Psychiatry and Behavioral Sciences, Vanderbilt University, Nashville, TN, USA
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20
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Activation of the mGlu 1 metabotropic glutamate receptor has antipsychotic-like effects and is required for efficacy of M 4 muscarinic receptor allosteric modulators. Mol Psychiatry 2020; 25:2786-2799. [PMID: 30116027 PMCID: PMC6588501 DOI: 10.1038/s41380-018-0206-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 06/01/2018] [Accepted: 06/28/2018] [Indexed: 12/25/2022]
Abstract
Recent clinical and preclinical studies suggest that selective activators of the M4 muscarinic acetylcholine receptor have potential as a novel treatment for schizophrenia. M4 activation inhibits striatal dopamine release by mobilizing endocannabinoids, providing a mechanism for local effects on dopamine signaling in the striatum but not in extrastriatal areas. G protein-coupled receptors (GPCRs) typically induce endocannabinoid release through activation of Gαq/11-type G proteins whereas M4 transduction occurs through Gαi/o-type G proteins. We now report that the ability of M4 to inhibit dopamine release and induce antipsychotic-like effects in animal models is dependent on co-activation of the Gαq/11-coupled mGlu1 subtype of metabotropic glutamate (mGlu) receptor. This is especially interesting in light of recent findings that multiple loss of function single nucleotide polymorphisms (SNPs) in the human gene encoding mGlu1 (GRM1) are associated with schizophrenia, and points to GRM1/mGlu1 as a gene within the "druggable genome" that could be targeted for the treatment of schizophrenia. Herein, we report that potentiation of mGlu1 signaling following thalamo-striatal stimulation is sufficient to inhibit striatal dopamine release, and that a novel mGlu1 positive allosteric modulator (PAM) exerts robust antipsychotic-like effects through an endocannabinoid-dependent mechanism. However, unlike M4, mGlu1 does not directly inhibit dopamine D1 receptor signaling and does not reduce motivational responding. Taken together, these findings highlight a novel mechanism of cross talk between mGlu1 and M4 and demonstrate that highly selective mGlu1 PAMs may provide a novel strategy for the treatment of positive symptoms associated with schizophrenia.
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21
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Masilamoni GJ, Smith Y. Group I metabotropic glutamate receptors in the primate motor thalamus: subsynaptic association with cortical and sub-cortical glutamatergic afferents. Brain Struct Funct 2019; 224:2787-2804. [PMID: 31422483 DOI: 10.1007/s00429-019-01937-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 08/07/2019] [Indexed: 12/21/2022]
Abstract
Preclinical evidence indicates that mGluR5 is a potential therapeutic target for Parkinson's disease and L-DOPA-induced dyskinesia. However, the mechanisms through which these therapeutic benefits are mediated remain poorly understood. Although the regulatory role of mGluR5 on glutamatergic transmission has been examined in various basal ganglia nuclei, very little is known about the localization and function of mGluR5 in the ventral motor and intralaminar thalamic nuclei, the main targets of basal ganglia output in mammals. Thus, we used immuno-electron microscopy to map the cellular and subcellular localization of group I mGluRs (mGluR1a and mGluR5) in the ventral motor and caudal intralaminar thalamic nuclei in rhesus monkeys. Furthermore, using double immuno-electron microscopy, we examined the subsynaptic localization of mGluR5 in relation to cortical and sub-cortical glutamatergic afferents. Four major conclusions can be drawn from these data. First, mGluR1a and mGluR5 are expressed postsynaptically on the plasma membrane of dendrites of projection neurons and GABAergic interneurons in the basal ganglia- and cerebellar-receiving regions of the ventral motor thalamus and in CM. Second, the plasma membrane-bound mGluR5 immunoreactivity is preferentially expressed perisynaptically at the edges of cortical and sub-cortical glutamatergic afferents. Third, the mGluR5 immunoreactivity is more strongly expressed in the lateral than the medial tiers of CM, suggesting a preferential association with thalamocortical over thalamostriatal neurons in the primate CM. Overall, mGluR5 is located to subserve powerful modulatory role of cortical and subcortical glutamatergic transmission in the primate ventral motor thalamus and CM.
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Affiliation(s)
- Gunasingh Jeyaraj Masilamoni
- Yerkes National Primate Research Center, Emory University, 954, Gatewood Rd NE, Atlanta, GA, 30329, USA. .,Udall Center of Excellence for Parkinson's Disease, Emory University School of Medicine, Atlanta, GA, 30322, USA.
| | - Yoland Smith
- Yerkes National Primate Research Center, Emory University, 954, Gatewood Rd NE, Atlanta, GA, 30329, USA.,Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA.,Udall Center of Excellence for Parkinson's Disease, Emory University School of Medicine, Atlanta, GA, 30322, USA
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22
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Schaffner A, Li X, Gomez-Llorente Y, Leandrou E, Memou A, Clemente N, Yao C, Afsari F, Zhi L, Pan N, Morohashi K, Hua X, Zhou MM, Wang C, Zhang H, Chen SG, Elliott CJ, Rideout H, Ubarretxena-Belandia I, Yue Z. Vitamin B 12 modulates Parkinson's disease LRRK2 kinase activity through allosteric regulation and confers neuroprotection. Cell Res 2019; 29:313-329. [PMID: 30858560 PMCID: PMC6462009 DOI: 10.1038/s41422-019-0153-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 02/09/2019] [Indexed: 12/12/2022] Open
Abstract
Missense mutations in Leucine-Rich Repeat Kinase 2 (LRRK2) cause the majority of familial and some sporadic forms of Parkinson's disease (PD). The hyperactivity of LRRK2 kinase induced by the pathogenic mutations underlies neurotoxicity, promoting the development of LRRK2 kinase inhibitors as therapeutics. Many potent and specific small-molecule LRRK2 inhibitors have been reported with promise. However, nearly all inhibitors are ATP competitive-some with unwanted side effects and unclear clinical outcome-alternative types of LRRK2 inhibitors are lacking. Herein we identify 5'-deoxyadenosylcobalamin (AdoCbl), a physiological form of the essential micronutrient vitamin B12 as a mixed-type allosteric inhibitor of LRRK2 kinase activity. Multiple assays show that AdoCbl directly binds LRRK2, leading to the alterations of protein conformation and ATP binding in LRRK2. STD-NMR analysis of a LRRK2 homologous kinase reveals the contact sites in AdoCbl that interface with the kinase domain. Furthermore, we provide evidence that AdoCbl modulates LRRK2 activity through disrupting LRRK2 dimerization. Treatment with AdoCbl inhibits LRRK2 kinase activity in cultured cells and brain tissue, and prevents neurotoxicity in cultured primary rodent neurons as well as in transgenic C. elegans and D. melanogaster expressing LRRK2 disease variants. Finally, AdoCbl alleviates deficits in dopamine release sustainability caused by LRRK2 disease variants in mouse models. Our study uncovers vitamin B12 as a novel class of LRRK2 kinase modulator with a distinct mechanism, which can be harnessed to develop new LRRK2-based PD therapeutics in the future.
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Affiliation(s)
- Adam Schaffner
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Xianting Li
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Yacob Gomez-Llorente
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Emmanouela Leandrou
- Division of Basic Neurosciences, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Anna Memou
- Division of Basic Neurosciences, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Nicolina Clemente
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Chen Yao
- Department of Pathology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Farinaz Afsari
- Department of Biology, University of York, York, YO1 5DD, UK
| | - Lianteng Zhi
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Nina Pan
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Keita Morohashi
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Xiaoluan Hua
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Ming-Ming Zhou
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Chunyu Wang
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Hui Zhang
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Shu G Chen
- Department of Pathology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | | | - Hardy Rideout
- Division of Basic Neurosciences, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Iban Ubarretxena-Belandia
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country, Leioa, Spain
| | - Zhenyu Yue
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
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23
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Zhi L, Qin Q, Muqeem T, Seifert EL, Liu W, Zheng S, Li C, Zhang H. Loss of PINK1 causes age-dependent decrease of dopamine release and mitochondrial dysfunction. Neurobiol Aging 2019; 75:1-10. [PMID: 30504091 PMCID: PMC6778692 DOI: 10.1016/j.neurobiolaging.2018.10.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 09/30/2018] [Accepted: 10/26/2018] [Indexed: 01/01/2023]
Abstract
Mutations and deletions in PTEN-induced kinase 1 (PINK1) cause autosomal recessive Parkinson's disease (PD), the second most common neurodegenerative disorder. PINK1 is a nuclear-genome encoded Ser/Thr kinase in mitochondria. PINK1 deletion was reported to affect dopamine (DA) levels in the striatum and mitochondrial functions but with conflicting results. The role of PINK1 in mitochondrial function and in PD pathogenesis remains to be elucidated thoroughly. In this study, we measured DA release using fast-scan cyclic voltammetry in acute striatal slices from both PINK1 knockout (KO) and wild-type (WT) mice at different ages. We found that single pulse-evoked DA release in the dorsal striatum of PINK1 KO mice was decreased in an age-dependent manner. Furthermore, the decrease was because of less DA release instead of an alteration of DA transporter function or DA terminal degeneration. We also found that PINK1 KO striatal slices had significantly lower basal mitochondria respiration compared with that of WT controls, and this impairment was also age-dependent. These results suggest that the impaired DA release is most likely because of mitochondrial dysfunction and lower ATP production.
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Affiliation(s)
- Lianteng Zhi
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - Qi Qin
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - Tanziyah Muqeem
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - Erin L Seifert
- Department of Pathology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Wencheng Liu
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York, NY, USA
| | - Sushuang Zheng
- School of Life Sciences, Peking University, Beijing, China
| | - Chenjian Li
- School of Life Sciences, Peking University, Beijing, China.
| | - Hui Zhang
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA.
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24
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Kang Y, Henchcliffe C, Verma A, Vallabhajosula S, He B, Kothari PJ, Pryor KO, Mozley PD. 18F-FPEB PET/CT Shows mGluR5 Upregulation in Parkinson's Disease. J Neuroimaging 2018; 29:97-103. [DOI: 10.1111/jon.12563] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 09/03/2018] [Accepted: 09/04/2018] [Indexed: 11/28/2022] Open
Affiliation(s)
- Yeona Kang
- Department of Radiology; Weill Cornell Medicine; New York NY
| | | | | | | | - Bin He
- Department of Radiology; Weill Cornell Medicine; New York NY
| | | | - Kane O. Pryor
- Department of Anesthesiology; Weill Cornell Medicine; New York NY
| | - P. David Mozley
- Department of Radiology; Weill Cornell Medicine; New York NY
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25
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Del-Bel E, De-Miguel FF. Extrasynaptic Neurotransmission Mediated by Exocytosis and Diffusive Release of Transmitter Substances. Front Synaptic Neurosci 2018; 10:13. [PMID: 29937726 PMCID: PMC6003215 DOI: 10.3389/fnsyn.2018.00013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 05/11/2018] [Indexed: 11/24/2022] Open
Abstract
This review article deals with the mechanisms of extrasynaptic release of transmitter substances, namely the release from the soma, axon and dendrites in the absence of postsynaptic counterparts. Extrasynaptic release occurs by exocytosis or diffusion. Spillover from the synaptic cleft also contributes to extrasynaptic neurotransmission. Here, we first describe two well-known examples of exocytosis from the neuronal soma, which may release copious amounts of transmitter for up to hundreds of seconds after electrical stimulation. The mechanisms for somatic exocytosis of the low molecular weight transmitter serotonin, and the peptides oxytocin and vasopressin have been studied in detail. Serotonin release from leech neurons and oxytocin and vasopressin from rodent neurons have a common multi-step mechanism, which is completely different from that for exocytosis from presynaptic endings. Most transmitters and peptides released extrasynaptically seem to follow this same mechanism. Extrasynaptic exocytosis may occur onto glial cells, which act as intermediaries for long-term and long-distance transmission. The second part of this review article focuses on the release upon synthesis of the representative diffusible molecules nitric oxide (NO) and endocannabinoids. Diffusible molecules are synthesized “on demand” from postsynaptic terminals in response to electrical activity and intracellular calcium elevations. Their effects include the retrograde modulation of presynaptic electrical activity and transmitter release. Extrasynaptic neurotransmission is well exemplified in the retina. Light-evoked extrasynaptic communication sets the gain for visual responses and integrates the activity of neurons, glia and blood vessels. Understanding how extrasynaptic communication changes the function of hard-wired circuits has become fundamental to understand the function of the nervous system.
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Affiliation(s)
- Elaine Del-Bel
- Department of Morphology Physiology and Basic Pathology, Dental School of Ribeirão Preto, USP-Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), University of São Paulo (USP), São Paulo, Brazil
| | - Francisco F De-Miguel
- Instituto de Fisiología Celular-Neurociencias, Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Mexico City, Mexico
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26
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Abstract
Cortical oscillations are thought to be involved in many cognitive functions and processes. Several mechanisms have been proposed to regulate oscillations. One prominent but understudied mechanism is gap junction coupling. Gap junctions are ubiquitous in cortex between GABAergic interneurons. Moreover, recent experiments indicate their strength can be modified in an activity-dependent manner, similar to chemical synapses. We hypothesized that activity-dependent gap junction plasticity acts as a mechanism to regulate oscillations in the cortex. We developed a computational model of gap junction plasticity in a recurrent cortical network based on recent experimental findings. We showed that gap junction plasticity can serve as a homeostatic mechanism for oscillations by maintaining a tight balance between two network states: asynchronous irregular activity and synchronized oscillations. This homeostatic mechanism allows for robust communication between neuronal assemblies through two different mechanisms: transient oscillations and frequency modulation. This implies a direct functional role for gap junction plasticity in information transmission in cortex.
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Affiliation(s)
- Guillaume Pernelle
- Bioengineering Department, Imperial College London, London, United Kingdom
| | - Wilten Nicola
- Bioengineering Department, Imperial College London, London, United Kingdom
| | - Claudia Clopath
- Bioengineering Department, Imperial College London, London, United Kingdom
- * E-mail:
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27
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Bamford NS, Wightman RM, Sulzer D. Dopamine's Effects on Corticostriatal Synapses during Reward-Based Behaviors. Neuron 2018; 97:494-510. [PMID: 29420932 PMCID: PMC5808590 DOI: 10.1016/j.neuron.2018.01.006] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 11/30/2017] [Accepted: 01/01/2018] [Indexed: 12/31/2022]
Abstract
Many learned responses depend on the coordinated activation and inhibition of synaptic pathways in the striatum. Local dopamine neurotransmission acts in concert with a variety of neurotransmitters to regulate cortical, thalamic, and limbic excitatory inputs to drive the direct and indirect striatal spiny projection neuron outputs that determine the activity, sequence, and timing of learned behaviors. We review recent advances in the characterization of stereotyped neuronal and operant responses that predict and then obtain rewards. These depend on the local release of dopamine at discrete times during behavioral sequences, which, acting with glutamate, provides a presynaptic filter to select which excitatory synapses are inhibited and which signals pass to indirect pathway circuits. This is followed by dopamine-dependent activation of specific direct pathway circuits to procure a reward. These steps may provide a means by which higher organisms learn behaviors in response to feedback from the environment.
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Affiliation(s)
- Nigel S Bamford
- Departments of Pediatrics, Neurology, Cellular and Molecular Physiology, Yale University, New Haven, CT 06510, USA.
| | - R Mark Wightman
- Department of Chemistry, University of North Carolina, Chapel Hill, NC, USA.
| | - David Sulzer
- Departments of Psychiatry, Neurology, Pharmacology, Columbia University Medical Campus, Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA.
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28
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Stansley BJ, Conn PJ. The therapeutic potential of metabotropic glutamate receptor modulation for schizophrenia. Curr Opin Pharmacol 2018; 38:31-36. [PMID: 29486374 PMCID: PMC5949078 DOI: 10.1016/j.coph.2018.02.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 02/10/2018] [Indexed: 12/21/2022]
Abstract
Accumulating evidence suggests that a dysregulation of the glutamatergic system exists in the brains of schizophrenia patients. The metabotropic glutamate (mGlu) receptors are being investigated as novel drug targets for this disease, and have shown promise in both preclinical and clinical studies. Activation of mGlu5 receptors may be efficacious for several symptom domains (positive, negative, and cognitive) and the potential for targeting mGlu5 receptors has been bolstered by recent research on mitigating toxicity profiles associated with mGlu5 activation. Additionally, genetic profiling of schizophrenia patients suggests that genes encoding for mGlu1 and mGlu3 receptors are altered, prompting preclinical studies that have demonstrated potential antipsychotic and cognitive enhancing effects of agents that activate mGlu1 and mGlu3 receptors, respectively. Development of subtype-specific drugs for the mGlu receptors, such as allosteric modulators, could provide a path forward for more efficacious and tolerable therapeutics for schizophrenia.
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Affiliation(s)
- Branden J Stansley
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - P Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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29
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Froudist-Walsh S, Bloomfield MA, Veronese M, Kroll J, Karolis VR, Jauhar S, Bonoldi I, McGuire PK, Kapur S, Murray RM, Nosarti C, Howes O. The effect of perinatal brain injury on dopaminergic function and hippocampal volume in adult life. eLife 2017; 6. [PMID: 29179814 PMCID: PMC5705207 DOI: 10.7554/elife.29088] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 11/02/2017] [Indexed: 11/21/2022] Open
Abstract
Perinatal brain injuries, including hippocampal lesions, cause lasting changes in dopamine function in rodents, but it is not known if this occurs in humans. We compared adults who were born very preterm with perinatal brain injury to those born very preterm without perinatal brain injury, and age-matched controls born at full term using [18F]-DOPA PET and structural MRI. Dopamine synthesis capacity was reduced in the perinatal brain injury group relative to those without brain injury (Cohen’s d = 1.36, p=0.02) and the control group (Cohen’s d = 1.07, p=0.01). Hippocampal volume was reduced in the perinatal brain injury group relative to controls (Cohen’s d = 1.17, p=0.01) and was positively correlated with striatal dopamine synthesis capacity (r = 0.344, p=0.03). This is the first evidence in humans linking neonatal hippocampal injury to adult dopamine dysfunction, and provides a potential mechanism linking early life risk factors to adult mental illness. Thirteen million infants are born too early every year. Improved care allows many to survive, but these “preterm infants” still face an increased risk of death and many other complications. Infants born very early, before 32 weeks, are at risk of brain injury because the brain is normally still developing in the later stages of pregnancy. They also have an increased risk of developing mental health problems later in life. Early-life brain injuries in rats cause changes in the production of a chemical called dopamine. Dopamine is a chemical messenger in the brain that reinforces rewarding behaviour. People with schizophrenia and attention deficit hyperactivity disorder (ADHD) have abnormal levels of dopamine. Changes in brain dopamine levels may explain why early-life brain injury is linked to later mental illness. But first scientists must study whether similar changes occur in humans with an early-life brain injury. Now, Froudist-Walsh et al. use brain imaging to show that people born very early who suffered a brain injury have lower dopamine levels than other adults. Imaging techniques were used to scan the brains of 13 adults who were born before 32 weeks and who had a brain injury around birth, 13 adults born before 32 weeks without a brain injury, and 13 adults born at “full term” (around 39 to 40 weeks). Individuals with low dopamine levels reported difficulty concentrating and a lack of motivation and enjoyment in their lives. Both can be warning signs of mental health problems. People born prematurely without a brain injury had normal dopamine levels and did not report such symptoms. More studies may help scientists understand how early brain injuries may cause brain chemical differences later in life, and how these brain changes affect individual’s mental health. They may also help scientists develop treatments to prevent or treat mental illness in people who experienced a brain injury after a very early birth.
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Affiliation(s)
- Sean Froudist-Walsh
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's Health Partners, King's College London, London, United Kingdom.,MRC Clinical Sciences Centre, Hammersmith Hospital, London, United Kingdom.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom.,Friedman Brain Institute, Fishberg Department of Neuroscience, Icahn School of Medicine, New York, United States
| | - Michael Ap Bloomfield
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's Health Partners, King's College London, London, United Kingdom.,MRC Clinical Sciences Centre, Hammersmith Hospital, London, United Kingdom.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom.,Division of Psychiatry, University College London, London, United Kingdom.,Clinical Psychopharmacology Unit, Research Department of Clinical, Educational and Health Psychology, University College London, London, United Kingdom
| | - Mattia Veronese
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's Health Partners, King's College London, London, United Kingdom
| | - Jasmin Kroll
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's Health Partners, King's College London, London, United Kingdom
| | - Vyacheslav R Karolis
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's Health Partners, King's College London, London, United Kingdom
| | - Sameer Jauhar
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's Health Partners, King's College London, London, United Kingdom.,MRC Clinical Sciences Centre, Hammersmith Hospital, London, United Kingdom.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Ilaria Bonoldi
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's Health Partners, King's College London, London, United Kingdom.,MRC Clinical Sciences Centre, Hammersmith Hospital, London, United Kingdom.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Philip K McGuire
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's Health Partners, King's College London, London, United Kingdom
| | - Shitij Kapur
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's Health Partners, King's College London, London, United Kingdom
| | - Robin M Murray
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's Health Partners, King's College London, London, United Kingdom
| | - Chiara Nosarti
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's Health Partners, King's College London, London, United Kingdom.,Centre for the Developing Brain, Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom
| | - Oliver Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's Health Partners, King's College London, London, United Kingdom.,MRC Clinical Sciences Centre, Hammersmith Hospital, London, United Kingdom.,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom
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30
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Maksymetz J, Moran SP, Conn PJ. Targeting metabotropic glutamate receptors for novel treatments of schizophrenia. Mol Brain 2017; 10:15. [PMID: 28446243 PMCID: PMC5405554 DOI: 10.1186/s13041-017-0293-z] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 04/04/2017] [Indexed: 12/22/2022] Open
Abstract
Support for the N-methyl-D-aspartate receptor (NMDAR) hypofunction hypothesis of schizophrenia has led to increasing focus on restoring proper glutamatergic signaling as an approach for treatment of this devastating disease. The ability of metabotropic glutamate (mGlu) receptors to modulate glutamatergic neurotransmission has thus attracted considerable attention for the development of novel antipsychotics. Consisting of eight subtypes classified into three groups based on sequence homology, signal transduction, and pharmacology, the mGlu receptors provide a wide range of targets to modulate NMDAR function as well as glutamate release. Recently, allosteric modulators of mGlu receptors have been developed that allow unprecedented selectivity among subtypes, not just groups, facilitating the investigation of the effects of subtype-specific modulation. In preclinical animal models, positive allosteric modulators (PAMs) of the group I mGlu receptor mGlu5 have efficacy across all three symptom domains of schizophrenia (positive, negative, and cognitive). The discovery and development of mGlu5 PAMs that display unique signal bias suggests that efficacy can be retained while avoiding the neurotoxic effects of earlier compounds. Interestingly, mGlu1 negative allosteric modulators (NAMs) appear efficacious in positive symptom models of the disease but are still in early preclinical development. While selective group II mGlu receptor (mGlu2/3) agonists have reached clinical trials but were unsuccessful, specific mGlu2 or mGlu3 receptor targeting still hold great promise. Genetic studies implicated mGlu2 in the antipsychotic effects of group II agonists and mGlu2 PAMs have since entered into clinical trials. Additionally, mGlu3 appears to play an important role in cognition, may confer neuroprotective effects, and thus is a promising target to alleviate cognitive deficits in schizophrenia. Although group III mGlu receptors (mGlu4/6/7/8) have attracted less attention, mGlu4 agonists and PAMs appear to have efficacy across all three symptoms domains in preclinical models. The recent discovery of heterodimers comprising mGlu2 and mGlu4 may explain the efficacy of mGlu4 selective compounds but this remains to be determined. Taken together, compounds targeting mGlu receptors, specifically subtype-selective allosteric modulators, provide a compelling alternative approach to fill the unmet clinical needs for patients with schizophrenia.
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Affiliation(s)
- James Maksymetz
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
- Vanderbilt Center for Neuroscience Drug Discovery, Nashville, TN 37232 USA
| | - Sean P. Moran
- Vanderbilt Center for Neuroscience Drug Discovery, Nashville, TN 37232 USA
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232 USA
| | - P. Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
- Vanderbilt Center for Neuroscience Drug Discovery, Nashville, TN 37232 USA
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232 USA
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31
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Endocannabinoid modulation of dopamine neurotransmission. Neuropharmacology 2017; 124:52-61. [PMID: 28450060 DOI: 10.1016/j.neuropharm.2017.04.033] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 04/20/2017] [Accepted: 04/23/2017] [Indexed: 12/15/2022]
Abstract
Dopamine (DA) is a major catecholamine neurotransmitter in the mammalian brain that controls neural circuits involved in the cognitive, emotional, and motor aspects of goal-directed behavior. Accordingly, perturbations in DA neurotransmission play a central role in several neuropsychiatric disorders. Somewhat surprisingly given its prominent role in numerous behaviors, DA is released by a relatively small number of densely packed neurons originating in the midbrain. The dopaminergic midbrain innervates numerous brain regions where extracellular DA release and receptor binding promote short- and long-term changes in postsynaptic neuron function. Striatal forebrain nuclei receive the greatest proportion of DA projections and are a predominant hub at which DA influences behavior. A number of excitatory, inhibitory, and modulatory inputs orchestrate DA neurotransmission by controlling DA cell body firing patterns, terminal release, and effects on postsynaptic sites in the striatum. The endocannabinoid (eCB) system serves as an important filter of afferent input that acts locally at midbrain and terminal regions to shape how incoming information is conveyed onto DA neurons and to output targets. In this review, we aim to highlight existing knowledge regarding how eCB signaling controls DA neuron function through modifications in synaptic strength at midbrain and striatal sites, and to raise outstanding questions on this topic. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".
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32
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Jin C, Ma S. Recent advances in the medicinal chemistry of group II and group III mGlu receptors. MEDCHEMCOMM 2017; 8:501-515. [PMID: 30108768 PMCID: PMC6072351 DOI: 10.1039/c6md00612d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 01/03/2017] [Indexed: 11/21/2022]
Abstract
Metabotropic glutamate receptors (mGlu receptors) belong to the G-protein-coupled receptors superfamily. They are divided into three groups, in which group II and group III belong to presynaptic receptors that negatively modulate glutamate and γ-aminobutyric acid (GABA) release when activated. In this review, we introduce not only the functions of mGlu receptors, but also the group II and group III allosteric modulators and agonists/antagonists reported over the past five years according to a classification of their structures, with a specific focus on their biological activity and selectivity. In particular, the structure of these compounds and the future directions of ideal candidates are highlighted.
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Affiliation(s)
- Chaobin Jin
- Department of Medicinal Chemistry , Key Laboratory of Chemical Biology (Ministry of Education) , School of Pharmaceutical Sciences , Shandong University , 44, West Culture Road , Jinan 250012 , P.R. China .
| | - Shutao Ma
- Department of Medicinal Chemistry , Key Laboratory of Chemical Biology (Ministry of Education) , School of Pharmaceutical Sciences , Shandong University , 44, West Culture Road , Jinan 250012 , P.R. China .
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33
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Yavas E, Young AMJ. N-Methyl-d-aspartate Modulation of Nucleus Accumbens Dopamine Release by Metabotropic Glutamate Receptors: Fast Cyclic Voltammetry Studies in Rat Brain Slices in Vitro. ACS Chem Neurosci 2017; 8:320-328. [PMID: 28121123 DOI: 10.1021/acschemneuro.6b00397] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The N-methyl-d-aspartate (NMDA) receptor antagonist, phencyclidine, induces behavioral changes in rodents mimicking symptoms of schizophrenia, possibly mediated through dysregulation of glutamatergic control of mesolimbic dopamine release. We tested the hypothesis that NMDA receptor activation modulates accumbens dopamine release, and that phencyclidine pretreatment altered this modulation. NMDA caused a receptor-specific, dose-dependent decrease in electrically stimulated dopamine release in nucleus accumbens brain slices. This decrease was unaffected by picrotoxin, making it unlikely to be mediated through GABAergic neurones, but was decreased by the metabotropic glutamate receptor antagonist, (RS)-α-methyl-4-sulfonophenylglycine, indicating that NMDA activates mechanisms controlled by these receptors to decrease stimulated dopamine release. The effect of NMDA was unchanged by in vivo pretreatment with phencyclidine (twice daily for 5 days), with a washout period of at least 7 days before experimentation, which supports the hypothesis that there is no enduring direct effect of PCP at NMDA receptors after this pretreatment procedure. We propose that NMDA depression of accumbal dopamine release is mediated by metabotropic glutamate receptors located pre- or perisynaptically, and suggest that NMDA evoked increased extrasynaptic spillover of glutamate is sufficient to activate these receptors that, in turn, inhibit dopamine release. Furthermore, we suggest that enduring functional changes brought about by subchronic phencyclidine pretreatment, modeling deficits in schizophrenia, are downstream effects consequent on chronic blockade of NMDA receptors, rather than direct effects on NMDA receptors themselves.
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Affiliation(s)
- Ersin Yavas
- Department of Neuroscience,
Psychology and Behaviour, University of Leicester, Lancaster Road, Leicester LE1 9HN, United Kingdom
| | - Andrew M. J. Young
- Department of Neuroscience,
Psychology and Behaviour, University of Leicester, Lancaster Road, Leicester LE1 9HN, United Kingdom
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34
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Qin Q, Zhi LT, Li XT, Yue ZY, Li GZ, Zhang H. Effects of LRRK2 Inhibitors on Nigrostriatal Dopaminergic Neurotransmission. CNS Neurosci Ther 2016; 23:162-173. [PMID: 27943591 PMCID: PMC5248597 DOI: 10.1111/cns.12660] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 10/31/2016] [Accepted: 10/31/2016] [Indexed: 12/13/2022] Open
Abstract
INTRODUCTION Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most prevalent cause of familial and sporadic Parkinson's disease (PD). Because most pathogenic LRRK2 mutations result in enhanced kinase activity, it suggests that LRRK2 inhibitors may serve as a potential treatment for PD. To evaluate whether LRRK2 inhibitors are effective therapies for PD, it is crucial to know whether LRRK2 inhibitors will affect dopaminergic (DAergic) neurotransmission. However, to date, there is no study to investigate the impact of LRRK2 inhibitors on DAergic neurotransmission. AIMS To address this gap in knowledge, we examined the effects of three types of LRRK2 inhibitors (LRRK2-IN-1, GSK2578215A, and GNE-7915) on dopamine (DA) release in the dorsal striatum using fast-scan cyclic voltammetry and DA neuron firing in the substantia nigra pars compacta (SNpc) using patch clamp in mouse brain slices. RESULTS We found that LRRK2-IN-1 at a concentration higher than 1 μM causes off-target effects and decreases DA release, whereas GSK2578215A and GNE-7915 do not. All three inhibitors at 1 μM have no effect on DA release and DA neuron firing rate. We have further assessed the effects of the inhibitors in two preclinical LRRK2 mouse models (i.e., BAC transgenic hG2019S and hR1441G) and demonstrated that GNE-7915 enhances DA release and synaptic vesicle mobilization/recycling. CONCLUSION GNE-7915 can be validated for further therapeutic development for PD.
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Affiliation(s)
- Qi Qin
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China.,Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - Lian-Teng Zhi
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - Xian-Ting Li
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Zhen-Yu Yue
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Guo-Zhong Li
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Hui Zhang
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
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35
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Kosillo P, Zhang YF, Threlfell S, Cragg SJ. Cortical Control of Striatal Dopamine Transmission via Striatal Cholinergic Interneurons. Cereb Cortex 2016; 26:4160-4169. [PMID: 27566978 PMCID: PMC5066833 DOI: 10.1093/cercor/bhw252] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 07/01/2016] [Accepted: 07/19/2016] [Indexed: 12/25/2022] Open
Abstract
Corticostriatal regulation of striatal dopamine (DA) transmission has long been postulated, but ionotropic glutamate receptors have not been localized directly to DA axons. Striatal cholinergic interneurons (ChIs) are emerging as major players in striatal function, and can govern DA transmission by activating nicotinic receptors (nAChRs) on DA axons. Cortical inputs to ChIs have historically been perceived as sparse, but recent evidence indicates that they strongly activate ChIs. We explored whether activation of M1/M2 corticostriatal inputs can consequently gate DA transmission, via ChIs. We reveal that optogenetic activation of channelrhodopsin-expressing corticostriatal axons can drive striatal DA release detected with fast-scan cyclic voltammetry and requires activation of nAChRs on DA axons and AMPA receptors on ChIs that promote short-latency action potentials. By contrast, DA release driven by optogenetic activation of intralaminar thalamostriatal inputs involves additional activation of NMDA receptors on ChIs and action potential generation over longer timescales. Therefore, cortical and thalamic glutamate inputs can modulate DA transmission by regulating ChIs as gatekeepers, through ionotropic glutamate receptors. The different use of AMPA and NMDA receptors by cortical versus thalamic inputs might lead to distinct input integration strategies by ChIs and distinct modulation of the function of DA and striatum.
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Affiliation(s)
- Polina Kosillo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.,Current address: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Yan-Feng Zhang
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Sarah Threlfell
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.,Oxford Parkinson's Disease Centre, University of Oxford, Oxford, OX1 3QX, UK
| | - Stephanie J Cragg
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.,Oxford Parkinson's Disease Centre, University of Oxford, Oxford, OX1 3QX, UK
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36
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Sulzer D, Cragg SJ, Rice ME. Striatal dopamine neurotransmission: regulation of release and uptake. ACTA ACUST UNITED AC 2016; 6:123-148. [PMID: 27141430 DOI: 10.1016/j.baga.2016.02.001] [Citation(s) in RCA: 236] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Dopamine (DA) transmission is governed by processes that regulate release from axonal boutons in the forebrain and the somatodendritic compartment in midbrain, and by clearance by the DA transporter, diffusion, and extracellular metabolism. We review how axonal DA release is regulated by neuronal activity and by autoreceptors and heteroreceptors, and address how quantal release events are regulated in size and frequency. In brain regions densely innervated by DA axons, DA clearance is due predominantly to uptake by the DA transporter, whereas in cortex, midbrain, and other regions with relatively sparse DA inputs, the norepinephrine transporter and diffusion are involved. We discuss the role of DA uptake in restricting the sphere of influence of DA and in temporal accumulation of extracellular DA levels upon successive action potentials. The tonic discharge activity of DA neurons may be translated into a tonic extracellular DA level, whereas their bursting activity can generate discrete extracellular DA transients.
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Affiliation(s)
- David Sulzer
- Depts of Psychiatry, Neurology, & Pharmacology, NY State Psychiatric Institute, Columbia University, New York, NY, USA
| | - Stephanie J Cragg
- Dept Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Margaret E Rice
- Depts of Neurosurgery & Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA
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37
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Pignatelli M, Bonci A. Role of Dopamine Neurons in Reward and Aversion: A Synaptic Plasticity Perspective. Neuron 2015; 86:1145-57. [PMID: 26050034 DOI: 10.1016/j.neuron.2015.04.015] [Citation(s) in RCA: 172] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The brain is wired to predict future outcomes. Experience-dependent plasticity at excitatory synapses within dopamine neurons of the ventral tegmental area, a key region for a broad range of motivated behaviors, is thought to be a fundamental cellular mechanism that enables adaptation to a dynamic environment. Thus, depending on the circumstances, dopamine neurons are capable of processing both positive and negative reinforcement learning strategies. In this review, we will discuss how changes in synaptic plasticity of dopamine neurons may affect dopamine release, as well as behavioral adaptations to different environmental conditions falling at opposite ends of a saliency spectrum ranging from reward to aversion.
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Affiliation(s)
- Marco Pignatelli
- Intramural Research Program, Synaptic Plasticity Section, National Institute on Drug Abuse, Baltimore, MD 21224, USA
| | - Antonello Bonci
- Intramural Research Program, Synaptic Plasticity Section, National Institute on Drug Abuse, Baltimore, MD 21224, USA; Solomon H. Snyder Neuroscience Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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38
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Melchior JR, Ferris MJ, Stuber GD, Riddle DR, Jones SR. Optogenetic versus electrical stimulation of dopamine terminals in the nucleus accumbens reveals local modulation of presynaptic release. J Neurochem 2015; 134:833-44. [PMID: 26011081 DOI: 10.1111/jnc.13177] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 05/07/2015] [Accepted: 05/13/2015] [Indexed: 12/24/2022]
Abstract
The nucleus accumbens is highly heterogeneous, integrating regionally distinct afferent projections and accumbal interneurons, resulting in diverse local microenvironments. Dopamine (DA) neuron terminals similarly express a heterogeneous collection of terminal receptors that modulate DA signaling. Cyclic voltammetry is often used to probe DA terminal dynamics in brain slice preparations; however, this method traditionally requires electrical stimulation to induce DA release. Electrical stimulation excites all of the neuronal processes in the stimulation field, potentially introducing simultaneous, multi-synaptic modulation of DA terminal release. We used optogenetics to selectively stimulate DA terminals and used voltammetry to compare DA responses from electrical and optical stimulation of the same area of tissue around a recording electrode. We found that with multiple pulse stimulation trains, optically stimulated DA release increasingly exceeded that of electrical stimulation. Furthermore, electrical stimulation produced inhibition of DA release across longer duration stimulations. The GABAB antagonist, CGP 55845, increased electrically stimulated DA release significantly more than light stimulated release. The nicotinic acetylcholine receptor antagonist, dihydro-β-erythroidine hydrobromide, inhibited single pulse electrically stimulated DA release while having no effect on optically stimulated DA release. Our results demonstrate that electrical stimulation introduces local multi-synaptic modulation of DA release that is absent with optogenetically targeted stimulation.
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Affiliation(s)
- James R Melchior
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Mark J Ferris
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Garret D Stuber
- Departments of Psychiatry and Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - David R Riddle
- Department of Biological Sciences, Western Michigan University School of Medicine, Kalamazoo, Michigan, USA
| | - Sara R Jones
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
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39
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Wong MY, Borgkvist A, Choi SJ, Mosharov EV, Bamford NS, Sulzer D. Dopamine-dependent corticostriatal synaptic filtering regulates sensorimotor behavior. Neuroscience 2015; 290:594-607. [PMID: 25637802 DOI: 10.1016/j.neuroscience.2015.01.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 01/12/2015] [Accepted: 01/15/2015] [Indexed: 10/24/2022]
Abstract
Modulation of corticostriatal synaptic activity by dopamine is required for normal sensorimotor behaviors. After loss of nigrostriatal dopamine axons in Parkinson's disease, l-3,4-dihydroxyphenlalanine (l-DOPA) and dopamine D2-like receptor agonists are used as replacement therapy, although these drugs also trigger sensitized sensorimotor responses including dyskinesias and impulse control disorders. In mice, we lesioned dopamine projections to the left dorsal striatum and assayed unilateral sensorimotor deficits with the corridor test as well as presynaptic corticostriatal activity with the synaptic vesicle probe, FM1-43. Sham-lesioned mice acquired food equivalently on both sides, while D2 receptor activation filtered the less active corticostriatal terminals, a response that required coincident co-activation of mGlu-R5 metabotropic glutamate and CB1 endocannabinoid receptors. Lesioned mice did not acquire food from their right, but overused that side following treatment with l-DOPA. Synaptic filtering on the lesioned side was abolished by either l-DOPA or a D2 receptor agonist, but when combined with a CB1 receptor antagonist, l-DOPA or D2 agonists normalized both synaptic filtering and behavior. Thus, high-pass filtering of corticostriatal synapses by the coordinated activation of D2, mGlu-R5, and CB1 receptors is required for normal sensorimotor response to environmental cues.
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Affiliation(s)
- M Y Wong
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
| | - A Borgkvist
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
| | - S J Choi
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
| | - E V Mosharov
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
| | - N S Bamford
- Departments of Neurology, Pediatrics and Psychology, University of Washington and Seattle Children's Hospital, Seattle, WA 98105, USA
| | - D Sulzer
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA; Department of Psychiatry, Columbia University Medical Center, New York State Psychiatric Institute, New York, NY 10032, USA; Department of Pharmacology, Columbia University Medical Center, New York, NY 10032, USA.
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Maex R, Grinevich VP, Grinevich V, Budygin E, Bencherif M, Gutkin B. Understanding the role α7 nicotinic receptors play in dopamine efflux in nucleus accumbens. ACS Chem Neurosci 2014; 5:1032-40. [PMID: 25147933 PMCID: PMC4198061 DOI: 10.1021/cn500126t] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
![]()
Neuronal nicotinic acetylcholine
receptors (NNRs) of the α7
subtype have been shown to contribute to the release of dopamine in
the nucleus accumbens. The site of action and the underlying mechanism,
however, are unclear. Here we applied a circuit modeling approach,
supported by electrochemical in vivo recordings, to clarify this issue.
Modeling revealed two potential mechanisms for the drop in accumbal
dopamine efflux evoked by the selective α7 partial agonist TC-7020.
TC-7020 could desensitize α7 NNRs located predominantly on dopamine
neurons or glutamatergic afferents to them or, alternatively, activate
α7 NNRs located on the glutamatergic afferents to GABAergic
interneurons in the ventral tegmental area. Only the model based on
desensitization, however, was able to explain the neutralizing effect
of coapplied PNU-120596, a positive allosteric modulator. According
to our results, the most likely sites of action are the preterminal
α7 NNRs controlling glutamate release from cortical afferents
to the nucleus accumbens. These findings offer a rationale for the
further investigation of α7 NNR agonists as therapy for diseases
associated with enhanced mesolimbic dopaminergic tone, such as schizophrenia
and addiction.
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Affiliation(s)
- Reinoud Maex
- Department
of Cognitive Sciences, École Normale Supérieure, Paris 75005, France
| | - Vladimir P. Grinevich
- Targacept Inc., Winston-Salem, North Carolina 27101, United States
- Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| | - Valentina Grinevich
- Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| | - Evgeny Budygin
- Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
- St. Petersburg State University, St. Petersburg 199034, Russia
| | | | - Boris Gutkin
- Department
of Cognitive Sciences, École Normale Supérieure, Paris 75005, France
- Center
for Cognition and Decision Making, National Research University Higher School of Economics, Moscow 101000, Russia
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41
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Cachope R, Cheer JF. Local control of striatal dopamine release. Front Behav Neurosci 2014; 8:188. [PMID: 24904339 PMCID: PMC4033078 DOI: 10.3389/fnbeh.2014.00188] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Accepted: 05/07/2014] [Indexed: 11/17/2022] Open
Abstract
The mesolimbic and nigrostriatal dopamine (DA) systems play a key role in the physiology of reward seeking, motivation and motor control. Importantly, they are also involved in the pathophysiology of Parkinson’s and Huntington’s disease, schizophrenia and addiction. Control of DA release in the striatum is tightly linked to firing of DA neurons in the ventral tegmental area (VTA) and the substantia nigra (SN). However, local influences in the striatum affect release by exerting their action directly on axon terminals. For example, endogenous glutamatergic and cholinergic activity is sufficient to trigger striatal DA release independently of cell body firing. Recent developments involving genetic manipulation, pharmacological selectivity or selective stimulation have allowed for better characterization of these phenomena. Such termino-terminal forms of control of DA release transform considerably our understanding of the mesolimbic and nigrostriatal systems, and have strong implications as potential mechanisms to modify impaired control of DA release in the diseased brain. Here, we review these and related mechanisms and their implications in the physiology of ascending DA systems.
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Affiliation(s)
- Roger Cachope
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine Baltimore, MD, USA ; CHDI Foundation Los Angeles, CA, USA
| | - Joseph F Cheer
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine Baltimore, MD, USA ; Department of Psychiatry, University of Maryland School of Medicine Baltimore, MD, USA
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42
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Ferris MJ, Milenkovic M, Liu S, Mielnik CA, Beerepoot P, John CE, España RA, Sotnikova TD, Gainetdinov RR, Borgland SL, Jones SR, Ramsey AJ. Sustained N-methyl-d-aspartate receptor hypofunction remodels the dopamine system and impairs phasic signaling. Eur J Neurosci 2014; 40:2255-63. [PMID: 24754704 DOI: 10.1111/ejn.12594] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 02/23/2014] [Accepted: 03/21/2014] [Indexed: 12/13/2022]
Abstract
Chronic N-methyl-d-aspartate receptor (NMDAR) hypofunction has been proposed as a contributing factor to symptoms of schizophrenia. However, it is unclear how sustained NMDAR hypofunction throughout development affects other neurotransmitter systems that have been implicated in the disease. Dopamine neuron biochemistry and activity were examined to determine whether sustained NMDAR hypofunction causes a state of hyperdopaminergia. We report that a global, genetic reduction in NMDARs led to a remodeling of dopamine neurons, substantially affecting two key regulators of dopamine homeostasis, i.e., tyrosine hydroxylase and the dopamine transporter. In NR1 knockdown mice, dopamine synthesis and release were attenuated, and dopamine clearance was increased. Although these changes would have the effect of reducing dopamine transmission, we demonstrated that a state of hyperdopaminergia existed in these mice because dopamine D2 autoreceptors were desensitized. In support of this conclusion, NR1 knockdown dopamine neurons have higher tonic firing rates. Although the tonic firing rates are higher, phasic signaling is impaired, and dopamine overflow cannot be achieved with exogenous high-frequency stimulation that models phasic firing. Through the examination of several parameters of dopamine neurotransmission, we provide evidence that chronic NMDAR hypofunction leads to a state of elevated synaptic dopamine. Compensatory mechanisms to attenuate hyperdopaminergia also impact the ability to generate dopamine surges through phasic firing.
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Affiliation(s)
- Mark J Ferris
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA
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43
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Freestone PS, Guatteo E, Piscitelli F, di Marzo V, Lipski J, Mercuri NB. Glutamate spillover drives endocannabinoid production and inhibits GABAergic transmission in the Substantia Nigra pars compacta. Neuropharmacology 2013; 79:467-75. [PMID: 24334069 DOI: 10.1016/j.neuropharm.2013.12.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 11/19/2013] [Accepted: 12/03/2013] [Indexed: 12/11/2022]
Abstract
Endocannabinoids (eCBs) modulate synaptic transmission in the brain, but little is known of their regulatory role in nigral dopaminergic neurons, and whether transmission to these neurons is tonically inhibited by eCBs as seen in some other brain regions. Using whole-cell recording in midbrain slices, we observed potentiation of evoked IPSCs (eIPSCs) in these neurons after blocking CB1 receptors with rimonabant or LY-320,135, indicating the presence of an eCB tone reducing inhibitory synaptic transmission. Increased postsynaptic calcium buffering and block of mGluR1 or postsynaptic G-protein coupled receptors prevented this potentiation. Increasing spillover of endogenous glutamate by inhibiting uptake attenuated eIPSC amplitude, while enhancing the potentiation by rimonabant. Group I mGluR activation transiently inhibited eIPSCs, which could be prevented by GDP-β-S, increased calcium buffering or rimonabant. We explored the possibility that the dopamine-derived eCB N-arachidonoyl dopamine (NADA) is involved. The eCB tone was abolished by preventing dopamine synthesis, and enhanced by l-DOPA. It was not detected in adjacent non-dopaminergic neurons. Preventing 2-AG synthesis did not affect the tone, while inhibition of NADA production abolished it. Quantification of ventral midbrain NADA suggested a basal level that increased following prolonged depolarization or mGluR activation. Since block of the tone was not always accompanied by attenuation of depolarization-induced suppression of inhibition (DSI) and vice versa, our results indicate DSI and the eCB tone are mediated by distinct eCBs. This study provides evidence that dopamine modulates the activity of SNc neurons not only by conventional dopamine receptors, but also by CB1 receptors, potentially via NADA.
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Affiliation(s)
- Peter S Freestone
- Department of Physiology and Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, New Zealand; Laboratorio di Neurologia Sperimentale, Fondazione Santa Lucia IRCCS, Rome, Italy
| | - Ezia Guatteo
- Laboratorio di Neurologia Sperimentale, Fondazione Santa Lucia IRCCS, Rome, Italy
| | - Fabiana Piscitelli
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, CNR, Pozzuoli, Italy
| | - Vincenzo di Marzo
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, CNR, Pozzuoli, Italy
| | - Janusz Lipski
- Department of Physiology and Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
| | - Nicola B Mercuri
- Laboratorio di Neurologia Sperimentale, Fondazione Santa Lucia IRCCS, Rome, Italy; Dipartimento di Medicina dei Sistemi, Universitá di Tor Vergata, Rome, Italy.
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44
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Patel JC, Rice ME. Classification of H₂O₂as a neuromodulator that regulates striatal dopamine release on a subsecond time scale. ACS Chem Neurosci 2012; 3:991-1001. [PMID: 23259034 DOI: 10.1021/cn300130b] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 10/15/2012] [Indexed: 01/18/2023] Open
Abstract
Here we review evidence that the reactive oxygen species, hydrogen peroxide (H(2)O(2)), meets the criteria for classification as a neuromodulator through its effects on striatal dopamine (DA) release. This evidence was obtained using fast-scan cyclic voltammetry to detect evoked DA release in striatal slices, along with whole-cell and fluorescence imaging to monitor cellular activity and H(2)O(2) generation in striatal medium spiny neurons (MSNs). The data show that (1) exogenous H(2)O(2) suppresses DA release in dorsal striatum and nucleus accumbens shell and the same effect is seen with elevation of endogenous H(2)O(2) levels; (2) H(2)O(2) is generated downstream from glutamatergic AMPA receptor activation in MSNs, but not DA axons; (3) generation of modulatory H(2)O(2) is activity dependent; (4) H(2)O(2) generated in MSNs diffuses to DA axons to cause transient DA release suppression by activating ATP-sensitive K(+) (K(ATP)) channels on DA axons; and (5) the amplitude of H(2)O(2)-dependent inhibition of DA release is attenuated by enzymatic degradation of H(2)O(2), but the subsecond time course is determined by H(2)O(2) diffusion rate and/or K(ATP)-channel kinetics. In the dorsal striatum, neuromodulatory H(2)O(2) is an intermediate in the regulation of DA release by the classical neurotransmitters glutamate and GABA, as well as other neuromodulators, including cannabinoids. However, modulatory actions of H(2)O(2) occur in other regions and cell types, as well, consistent with the widespread expression of K(ATP) and other H(2)O(2)-sensitive channels throughout the CNS.
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Affiliation(s)
- Jyoti C. Patel
- Department
of Neurosurgery, ‡Department of Physiology and Neuroscience, New York University School of Medicine, 550 First Avenue,
New York, New York 10016, United States
| | - Margaret E. Rice
- Department
of Neurosurgery, ‡Department of Physiology and Neuroscience, New York University School of Medicine, 550 First Avenue,
New York, New York 10016, United States
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45
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Xu C, Zhao J, Liu Y, Zeng X, Jia Y, Wang Y, Jiang X, Xu Q. Dopaminergic axons preferentially innervate dendritic spines with hyperactive glutamatergic synapses in the rat striatum. Brain Res 2012; 1486:92-102. [PMID: 23010310 DOI: 10.1016/j.brainres.2012.09.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 09/08/2012] [Accepted: 09/18/2012] [Indexed: 01/01/2023]
Abstract
Dopaminergic and glutamatergic afferents simultaneously innervate median spiny neurons (MSNs) and interact to mediate basal ganglia functions. However, the association between dopaminergic and glutamatergic axons is not clear. In the present study, nigrostriatal, corticostriatal, and thalamostriatal axons were anterogradely traced with biotinylated dextran amines (BDA) in rats, and MSNs were labeled with chloromethylbenzamido-DiI for neurogeometric analysis. Results showed that nigrostriatal, but not corticostriatal or thalamostriatal, axons were biased to a target on dendritic spines of the MSNs. In addition, the MSN dendritic spines, which were innervated by tyrosine hydroxylase-immunoreactive (TH-IR) axons and vesicular glutamate transporter 1 or 2-immunoreactive (VGluT-IR) terminals, were significantly larger than dendritic spines innervated by VGluT-IR terminals alone. Under electron microscopy, glutamatergic synapses on the dendritic spines were located with TH-IR terminals and displayed longer postsynaptic density. In addition, these synapses were more perforated than those on dendritic spines lacking innervated TH-IR terminals. These results demonstrated that dopaminergic axons were biased to a target and preferred to innervate dendritic spines with hyperactive and high-efficacy glutamatergic synapses in the striatum.
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Affiliation(s)
- Changlei Xu
- Beijing Institute for Neuroscience, Beijing Center of Neural Regeneration and Repairing, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Capital Medical University, Beijing 100069, PR China
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46
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de Bartolomeis A, Tomasetti C. Calcium-Dependent Networks in Dopamine–Glutamate Interaction: The Role of Postsynaptic Scaffolding Proteins. Mol Neurobiol 2012; 46:275-96. [DOI: 10.1007/s12035-012-8293-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 06/21/2012] [Indexed: 01/11/2023]
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47
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Quik M, Wonnacott S. α6β2* and α4β2* nicotinic acetylcholine receptors as drug targets for Parkinson's disease. Pharmacol Rev 2012; 63:938-66. [PMID: 21969327 DOI: 10.1124/pr.110.003269] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Parkinson's disease is a debilitating movement disorder characterized by a generalized dysfunction of the nervous system, with a particularly prominent decline in the nigrostriatal dopaminergic pathway. Although there is currently no cure, drugs targeting the dopaminergic system provide major symptomatic relief. As well, agents directed to other neurotransmitter systems are of therapeutic benefit. Such drugs may act by directly improving functional deficits in these other systems, or they may restore aberrant motor activity that arises as a result of a dopaminergic imbalance. Recent research attention has focused on a role for drugs targeting the nicotinic cholinergic systems. The rationale for such work stems from basic research findings that there is an extensive overlap in the organization and function of the nicotinic cholinergic and dopaminergic systems in the basal ganglia. In addition, nicotinic acetylcholine receptor (nAChR) drugs could have clinical potential for Parkinson's disease. Evidence for this proposition stems from studies with experimental animal models showing that nicotine protects against neurotoxin-induced nigrostriatal damage and improves motor complications associated with l-DOPA, the "gold standard" for Parkinson's disease treatment. Nicotine interacts with multiple central nervous system receptors to generate therapeutic responses but also produces side effects. It is important therefore to identify the nAChR subtypes most beneficial for treating Parkinson's disease. Here we review nAChRs with particular emphasis on the subtypes that contribute to basal ganglia function. Accumulating evidence suggests that drugs targeting α6β2* and α4β2* nAChR may prove useful in the management of Parkinson's disease.
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Affiliation(s)
- Maryka Quik
- Center for Health Sciences, SRI International, Menlo Park, CA 94025, USA.
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48
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Striatal dopamine transmission is subtly modified in human A53Tα-synuclein overexpressing mice. PLoS One 2012; 7:e36397. [PMID: 22570709 PMCID: PMC3343082 DOI: 10.1371/journal.pone.0036397] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 04/06/2012] [Indexed: 11/19/2022] Open
Abstract
Mutations in, or elevated dosage of, SNCA, the gene for α-synuclein (α-syn), cause familial Parkinson's disease (PD). Mouse lines overexpressing the mutant human A53Tα-syn may represent a model of early PD. They display progressive motor deficits, abnormal cellular accumulation of α-syn, and deficits in dopamine-dependent corticostriatal plasticity, which, in the absence of overt nigrostriatal degeneration, suggest there are age-related deficits in striatal dopamine (DA) signalling. In addition A53Tα-syn overexpression in cultured rodent neurons has been reported to inhibit transmitter release. Therefore here we have characterized for the first time DA release in the striatum of mice overexpressing human A53Tα-syn, and explored whether A53Tα-syn overexpression causes deficits in the release of DA. We used fast-scan cyclic voltammetry to detect DA release at carbon-fibre microelectrodes in acute striatal slices from two different lines of A53Tα-syn-overexpressing mice, at up to 24 months. In A53Tα-syn overexpressors, mean DA release evoked by a single stimulus pulse was not different from wild-types, in either dorsal striatum or nucleus accumbens. However the frequency responsiveness of DA release was slightly modified in A53Tα-syn overexpressors, and in particular showed slight deficiency when the confounding effects of striatal ACh acting at presynaptic nicotinic receptors (nAChRs) were antagonized. The re-release of DA was unmodified after single-pulse stimuli, but after prolonged stimulation trains, A53Tα-syn overexpressors showed enhanced recovery of DA release at old age, in keeping with elevated striatal DA content. In summary, A53Tα-syn overexpression in mice causes subtle changes in the regulation of DA release in the striatum. While modest, these modifications may indicate or contribute to striatal dysfunction.
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Mishra D, Zhang X, Chergui K. Ethanol disrupts the mechanisms of induction of long-term potentiation in the mouse nucleus accumbens. Alcohol Clin Exp Res 2012; 36:2117-25. [PMID: 22551245 DOI: 10.1111/j.1530-0277.2012.01824.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 03/06/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND Long-term changes in the efficacy of glutamatergic synaptic transmission in reward-related brain regions such as the nucleus accumbens (NAc) are proposed to contribute to neuroadaptations that lead to drug addiction. Although alcohol is a widely used addictive substance, the cellular mechanisms by which it influences synaptic plasticity in the NAc are not elucidated. We therefore examined whether acute ethanol (EtOH) alters long-term potentiation (LTP) in the core region of the NAc and investigated the possible underlying mechanisms. METHODS We measured field excitatory postsynaptic potential/population spike (fEPSP/PS) amplitude in mouse brain slices containing the NAc. We also used amperometry to detect, with carbon fiber electrode, evoked dopamine release in brain slices. RESULTS In control slices, high-frequency stimulation (HFS) induced a stable LTP. LTP was reduced in slices perfused with EtOH (50 mM). Given that induction of LTP is dependent on glutamate acting on N-methyl-d-aspartate (NMDA) receptors and group I metabotropic glutamate receptors (mGluRs), we studied the ability of EtOH to modulate these 2 classes of receptors. NMDA (20 μM) depressed the amplitude of the fEPSP/PS, but this effect was not altered by EtOH in our experimental conditions. However, EtOH reversed the ability of the group I mGluR agonist (S)-3,5-Dihydroxyphenylglycine (DHPG) (50 μM) to potentiate the depressant action of NMDA on the fEPSP/PS. We also examined whether EtOH could modulate dopamine release given that dopamine plays important roles in mediating the reinforcing actions of abused drugs and in the induction of LTP in the NAc. We found that EtOH reversibly decreased action potential-dependent dopamine release evoked by single stimulation pulses and by HFS trains in NAc slices. CONCLUSIONS These results show that EtOH impairs the induction of LTP possibly through several mechanisms that include inhibition of group I mGluR-mediated potentiation of NMDA receptor function and of evoked dopamine release. This study provides additional support for a key role of glutamatergic and dopaminergic neurotransmission in the NAc in mediating the reinforcing effects of acute alcohol.
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Affiliation(s)
- Devesh Mishra
- Section of Molecular Neurophysiology , Department of Physiology and Pharmacology, The Karolinska Institute, Stockholm, Sweden
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Zhang H, Sulzer D. Regulation of striatal dopamine release by presynaptic auto- and heteroreceptors. ACTA ACUST UNITED AC 2012; 2:5-13. [PMID: 22712055 DOI: 10.1016/j.baga.2011.11.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Striatal dopamine neurotransmission is critical for normal voluntary movement, affect and cognition. Dysfunctions of its regulation are implicated in a broad range of behaviors and disorders including Parkinson's disease, schizophrenia and drug abuse. Extracellular dopamine levels result from a dynamic equilibrium between release and reuptake by dopaminergic terminals. Both processes are regulated by multiple mechanisms. Here we review data characterizing how dopamine levels are regulated by presynaptic autoreceptors and heteroreceptors, an area intensively investigated due to advances in real time electrochemical detection of extracellular dopamine, i.e., fast-scan cyclic voltammetry and amperometry, and the development of mutant mouse lines with deletions for specific receptors.
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Affiliation(s)
- Hui Zhang
- Department of Psychiatry and Neurology, Columbia University, New York
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